From a0ac2a63d4b21455985436fbc70192da14a163fd Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 16 Jun 2026 07:58:45 -0400 Subject: nfsd: add protocol support for CB_NOTIFY Add the necessary bits to nfs4_1.x and remove the duplicate definitions from nfs4.h and the uapi nfs4 header. Regenerate the xdr files. Note that regenerating these files caused conflicts with the definitions of NFS4_VERIFIER_SIZE and NFS4_FHSIZE in include/uapi/linux/nfs4.h. These constants are defined by the RFC, and are not part of the kernel API. They have been removed. Userspace consumers who require those constants should plan to get them from more authoritative sources. The nfsstat4 enum defined in the .x is fed to the xdrgen-generated wire encoder and decoder, which treat every enumerated value as legal on the wire. Do not carry the NFS4ERR_FIRST_FREE sentinel (which is not a protocol error code) into the .x; keeping it would make 10097 a value that could leak onto the wire. Instead base nfsd's internal error codes (NFSERR_EOF and friends) at an impossible nfsstat4 value, as lockd does for its nlm__int__* status codes. Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260616-dir-deleg-v7-2-6cbc7eac0ade@kernel.org Signed-off-by: Chuck Lever --- include/uapi/linux/nfs4.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'include/uapi') diff --git a/include/uapi/linux/nfs4.h b/include/uapi/linux/nfs4.h index 4273e0249fcb..289205b53a08 100644 --- a/include/uapi/linux/nfs4.h +++ b/include/uapi/linux/nfs4.h @@ -17,11 +17,9 @@ #include #define NFS4_BITMAP_SIZE 3 -#define NFS4_VERIFIER_SIZE 8 #define NFS4_STATEID_SEQID_SIZE 4 #define NFS4_STATEID_OTHER_SIZE 12 #define NFS4_STATEID_SIZE (NFS4_STATEID_SEQID_SIZE + NFS4_STATEID_OTHER_SIZE) -#define NFS4_FHSIZE 128 #define NFS4_MAXPATHLEN PATH_MAX #define NFS4_MAXNAMLEN NAME_MAX #define NFS4_OPAQUE_LIMIT 1024 -- cgit From 36ed32f46e2aa35084fa0e6edecc3f0a6178489f Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 17 Jul 2026 07:08:55 -0400 Subject: nfsd: implement server-stats-get netlink handler Implement nfsd_nl_server_stats_get_dumpit() which exposes the NFS server statistics currently available via /proc/net/rpc/nfsd through the nfsd generic netlink family. The handler uses a dump operation to stream statistics across one or more netlink messages. The reply is divided into sections that are emitted in order: - scalar stats (reply cache, filehandle, IO, network, RPC), emitted once in the first message, then - per-version procedure counts (proc2/3/4-ops) and the NFSv4 per-operation counts (proc4ops-ops), using the per-netns vs_count arrays. cb->args[0] tracks the current section and cb->args[1] the entry index within it, so a section that does not fit in the current message is closed and resumed in the next one. This matters because the first dump message is allocated at NLMSG_GOODSIZE (a single page on most architectures) regardless of the client's receive buffer; packing every counter into one message would overflow it and fail the dump with -EMSGSIZE. Userspace merges the attributes from every message. This allows nfsstat to retrieve server statistics via netlink with a procfs fallback for older kernels. Assisted-by: LLM Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260717-exportd-netlink-v7-3-b7ce17b83b60@kernel.org Signed-off-by: Chuck Lever --- Documentation/netlink/specs/nfsd.yaml | 105 ++++++++++++++++ fs/nfsd/netlink.c | 5 + fs/nfsd/netlink.h | 2 + fs/nfsd/nfsctl.c | 222 ++++++++++++++++++++++++++++++++++ include/uapi/linux/nfsd_netlink.h | 35 ++++++ 5 files changed, 369 insertions(+) (limited to 'include/uapi') diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlink/specs/nfsd.yaml index 8f36fadd68f7..2a89d355ee7b 100644 --- a/Documentation/netlink/specs/nfsd.yaml +++ b/Documentation/netlink/specs/nfsd.yaml @@ -330,6 +330,86 @@ attribute-sets: of which client holds the state. Intended for use after all clients have been unexported from a given path, enabling the underlying filesystem to be unmounted. + - + name: server-proc-entry + attributes: + - + name: op + type: u32 + - + name: count + type: u64 + - + name: pad + type: pad + - + name: server-stats + attributes: + - + name: rc-hits + type: u64 + - + name: rc-misses + type: u64 + - + name: rc-nocache + type: u64 + - + name: pad + type: pad + - + name: fh-stale + type: u64 + - + name: io-read + type: u64 + - + name: io-write + type: u64 + - + name: netcnt + type: u32 + - + name: netudpcnt + type: u32 + - + name: nettcpcnt + type: u32 + - + name: nettcpconn + type: u32 + - + name: rpccnt + type: u32 + - + name: rpcbadfmt + type: u32 + - + name: rpcbadauth + type: u32 + - + name: rpcbadclnt + type: u32 + - + name: proc2-ops + type: nest + nested-attributes: server-proc-entry + multi-attr: true + - + name: proc3-ops + type: nest + nested-attributes: server-proc-entry + multi-attr: true + - + name: proc4-ops + type: nest + nested-attributes: server-proc-entry + multi-attr: true + - + name: proc4ops-ops + type: nest + nested-attributes: server-proc-entry + multi-attr: true operations: list: @@ -516,6 +596,31 @@ operations: request: attributes: - path + - + name: server-stats-get + doc: dump NFS server statistics + attribute-set: server-stats + dump: + reply: + attributes: + - rc-hits + - rc-misses + - rc-nocache + - fh-stale + - io-read + - io-write + - netcnt + - netudpcnt + - nettcpcnt + - nettcpconn + - rpccnt + - rpcbadfmt + - rpcbadauth + - rpcbadclnt + - proc2-ops + - proc3-ops + - proc4-ops + - proc4ops-ops mcast-groups: list: diff --git a/fs/nfsd/netlink.c b/fs/nfsd/netlink.c index fbee3676d253..eba8b353f412 100644 --- a/fs/nfsd/netlink.c +++ b/fs/nfsd/netlink.c @@ -225,6 +225,11 @@ static const struct genl_split_ops nfsd_nl_ops[] = { .maxattr = NFSD_A_UNLOCK_EXPORT_PATH, .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO, }, + { + .cmd = NFSD_CMD_SERVER_STATS_GET, + .dumpit = nfsd_nl_server_stats_get_dumpit, + .flags = GENL_CMD_CAP_DUMP, + }, }; static const struct genl_multicast_group nfsd_nl_mcgrps[] = { diff --git a/fs/nfsd/netlink.h b/fs/nfsd/netlink.h index af41aa0d4a65..027e2953db26 100644 --- a/fs/nfsd/netlink.h +++ b/fs/nfsd/netlink.h @@ -42,6 +42,8 @@ int nfsd_nl_cache_flush_doit(struct sk_buff *skb, struct genl_info *info); int nfsd_nl_unlock_ip_doit(struct sk_buff *skb, struct genl_info *info); int nfsd_nl_unlock_filesystem_doit(struct sk_buff *skb, struct genl_info *info); int nfsd_nl_unlock_export_doit(struct sk_buff *skb, struct genl_info *info); +int nfsd_nl_server_stats_get_dumpit(struct sk_buff *skb, + struct netlink_callback *cb); enum { NFSD_NLGRP_NONE, diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index ae5a7f1ad917..7731051105c9 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2331,6 +2331,228 @@ int nfsd_nl_cache_flush_doit(struct sk_buff *skb, struct genl_info *info) return 0; } +/* Emit a single server-proc-entry nest: { op, count }. */ +static int nfsd_nl_put_proc_entry(struct sk_buff *skb, int attr, + u32 op, u64 count) +{ + struct nlattr *nest; + + nest = nla_nest_start(skb, attr); + if (!nest) + return -EMSGSIZE; + if (nla_put_u32(skb, NFSD_A_SERVER_PROC_ENTRY_OP, op) || + nla_put_u64_64bit(skb, NFSD_A_SERVER_PROC_ENTRY_COUNT, + count, NFSD_A_SERVER_PROC_ENTRY_PAD)) { + nla_nest_cancel(skb, nest); + return -EMSGSIZE; + } + nla_nest_end(skb, nest); + return 0; +} + +/* Emit the scalar server-stats counters. Only ever called on a fresh skb. */ +static int nfsd_nl_server_stats_scalars(struct sk_buff *skb, + struct nfsd_net *nn, + struct svc_stat *statp) +{ + if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_HITS, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_HITS]), + NFSD_A_SERVER_STATS_PAD) || + nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_MISSES, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_MISSES]), + NFSD_A_SERVER_STATS_PAD) || + nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_RC_NOCACHE, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_RC_NOCACHE]), + NFSD_A_SERVER_STATS_PAD)) + return -EMSGSIZE; + + if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_FH_STALE, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_FH_STALE]), + NFSD_A_SERVER_STATS_PAD)) + return -EMSGSIZE; + + if (nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_IO_READ, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_READ]), + NFSD_A_SERVER_STATS_PAD) || + nla_put_u64_64bit(skb, NFSD_A_SERVER_STATS_IO_WRITE, + percpu_counter_sum_positive(&nn->counter[NFSD_STATS_IO_WRITE]), + NFSD_A_SERVER_STATS_PAD)) + return -EMSGSIZE; + + if (nla_put_u32(skb, NFSD_A_SERVER_STATS_NETCNT, statp->netcnt) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_NETUDPCNT, statp->netudpcnt) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_NETTCPCNT, statp->nettcpcnt) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_NETTCPCONN, statp->nettcpconn)) + return -EMSGSIZE; + + if (nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCCNT, statp->rpccnt) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADFMT, statp->rpcbadfmt) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADAUTH, statp->rpcbadauth) || + nla_put_u32(skb, NFSD_A_SERVER_STATS_RPCBADCLNT, statp->rpcbadclnt)) + return -EMSGSIZE; + + return 0; +} + +/* + * Emit per-version procedure counts for one NFS version, resuming at *idx. + * Returns 0 when the version has been fully emitted (or is not present), or + * -EMSGSIZE when @skb filled up, leaving *idx at the entry still to emit. + */ +static int nfsd_nl_server_stats_proc(struct sk_buff *skb, + struct svc_stat *statp, + struct svc_program *prog, + unsigned int ver, int attr, int *idx) +{ + unsigned long __percpu *counts; + unsigned int nproc; + + if (!statp->vs_count || ver >= prog->pg_nvers || + !prog->pg_vers[ver] || !statp->vs_count[ver]) + return 0; + + counts = statp->vs_count[ver]; + nproc = prog->pg_vers[ver]->vs_nproc; + + for (; *idx < nproc; (*idx)++) { + unsigned long count = 0; + int cpu; + + for_each_possible_cpu(cpu) + count += per_cpu(counts[*idx], cpu); + + if (!count) + continue; + if (nfsd_nl_put_proc_entry(skb, attr, *idx, count)) + return -EMSGSIZE; + } + + return 0; +} + +#ifdef CONFIG_NFSD_V4 +/* + * Emit NFSv4 per-operation counts, resuming at *idx. Same return convention + * as nfsd_nl_server_stats_proc(). + */ +static int nfsd_nl_server_stats_nfs4ops(struct sk_buff *skb, + struct nfsd_net *nn, int *idx) +{ + for (; *idx <= LAST_NFS4_OP; (*idx)++) { + u64 cnt = percpu_counter_sum_positive( + &nn->counter[NFSD_STATS_NFS4_OP(*idx)]); + + if (!cnt) + continue; + if (nfsd_nl_put_proc_entry(skb, NFSD_A_SERVER_STATS_PROC4OPS_OPS, + *idx, cnt)) + return -EMSGSIZE; + } + + return 0; +} +#endif + +/* Sections of the server-stats dump, emitted in order across messages. */ +enum { + NFSD_SERVER_STATS_SCALARS = 0, + NFSD_SERVER_STATS_PROC2, + NFSD_SERVER_STATS_PROC3, + NFSD_SERVER_STATS_PROC4, + NFSD_SERVER_STATS_PROC4OPS, + NFSD_SERVER_STATS_DONE, +}; + +/** + * nfsd_nl_server_stats_get_dumpit - dump NFS server statistics + * @skb: reply buffer + * @cb: netlink metadata and command arguments + * + * The server-stats object is emitted across one or more netlink messages. + * cb->args[0] tracks the current section and cb->args[1] the entry index + * within it, so a section that does not fit in the current message is resumed + * in the next one. The scalar counters are small and emitted once, in the + * first message; userspace merges the attributes from every message. + * + * Returns the size of the reply or a negative errno. + */ +int nfsd_nl_server_stats_get_dumpit(struct sk_buff *skb, + struct netlink_callback *cb) +{ + struct net *net = sock_net(skb->sk); + struct nfsd_net *nn = net_generic(net, nfsd_net_id); + struct svc_stat *statp = &nn->nfsd_svcstats; + struct svc_program *prog = statp->program; + int section = cb->args[0]; + int idx = cb->args[1]; + void *hdr; + + if (section >= NFSD_SERVER_STATS_DONE) + return 0; + + hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, &nfsd_nl_family, + NLM_F_MULTI, NFSD_CMD_SERVER_STATS_GET); + if (!hdr) + return -ENOBUFS; + + /* Scalar stats fit easily and are emitted in the first message. */ + if (section == NFSD_SERVER_STATS_SCALARS) { + if (nfsd_nl_server_stats_scalars(skb, nn, statp)) + goto err_cancel; + section = NFSD_SERVER_STATS_PROC2; + idx = 0; + } + + /* + * Emit as many of the remaining sections as fit. A section returning + * -EMSGSIZE means the message is full: close it and resume from the + * same section/index on the next call with a fresh skb. Each entry is + * small enough to fit in a fresh skb, so forward progress is assured. + */ + while (section < NFSD_SERVER_STATS_DONE) { + int ret = 0; + + switch (section) { + case NFSD_SERVER_STATS_PROC2: + ret = nfsd_nl_server_stats_proc(skb, statp, prog, 2, + NFSD_A_SERVER_STATS_PROC2_OPS, &idx); + break; + case NFSD_SERVER_STATS_PROC3: + ret = nfsd_nl_server_stats_proc(skb, statp, prog, 3, + NFSD_A_SERVER_STATS_PROC3_OPS, &idx); + break; + case NFSD_SERVER_STATS_PROC4: + ret = nfsd_nl_server_stats_proc(skb, statp, prog, 4, + NFSD_A_SERVER_STATS_PROC4_OPS, &idx); + break; +#ifdef CONFIG_NFSD_V4 + case NFSD_SERVER_STATS_PROC4OPS: + ret = nfsd_nl_server_stats_nfs4ops(skb, nn, &idx); + break; +#endif + } + + if (ret == -EMSGSIZE) + goto out; + if (ret) + goto err_cancel; + + section++; + idx = 0; + } + +out: + genlmsg_end(skb, hdr); + cb->args[0] = section; + cb->args[1] = idx; + return skb->len; + +err_cancel: + genlmsg_cancel(skb, hdr); + return -EMSGSIZE; +} + int nfsd_cache_notify(struct cache_detail *cd, struct cache_head *h, u32 cache_type) { struct genlmsghdr *hdr; diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/nfsd_netlink.h index f5b75d5caba9..3d076d173b1d 100644 --- a/include/uapi/linux/nfsd_netlink.h +++ b/include/uapi/linux/nfsd_netlink.h @@ -225,6 +225,40 @@ enum { NFSD_A_UNLOCK_EXPORT_MAX = (__NFSD_A_UNLOCK_EXPORT_MAX - 1) }; +enum { + NFSD_A_SERVER_PROC_ENTRY_OP = 1, + NFSD_A_SERVER_PROC_ENTRY_COUNT, + NFSD_A_SERVER_PROC_ENTRY_PAD, + + __NFSD_A_SERVER_PROC_ENTRY_MAX, + NFSD_A_SERVER_PROC_ENTRY_MAX = (__NFSD_A_SERVER_PROC_ENTRY_MAX - 1) +}; + +enum { + NFSD_A_SERVER_STATS_RC_HITS = 1, + NFSD_A_SERVER_STATS_RC_MISSES, + NFSD_A_SERVER_STATS_RC_NOCACHE, + NFSD_A_SERVER_STATS_PAD, + NFSD_A_SERVER_STATS_FH_STALE, + NFSD_A_SERVER_STATS_IO_READ, + NFSD_A_SERVER_STATS_IO_WRITE, + NFSD_A_SERVER_STATS_NETCNT, + NFSD_A_SERVER_STATS_NETUDPCNT, + NFSD_A_SERVER_STATS_NETTCPCNT, + NFSD_A_SERVER_STATS_NETTCPCONN, + NFSD_A_SERVER_STATS_RPCCNT, + NFSD_A_SERVER_STATS_RPCBADFMT, + NFSD_A_SERVER_STATS_RPCBADAUTH, + NFSD_A_SERVER_STATS_RPCBADCLNT, + NFSD_A_SERVER_STATS_PROC2_OPS, + NFSD_A_SERVER_STATS_PROC3_OPS, + NFSD_A_SERVER_STATS_PROC4_OPS, + NFSD_A_SERVER_STATS_PROC4OPS_OPS, + + __NFSD_A_SERVER_STATS_MAX, + NFSD_A_SERVER_STATS_MAX = (__NFSD_A_SERVER_STATS_MAX - 1) +}; + enum { NFSD_CMD_RPC_STATUS_GET = 1, NFSD_CMD_THREADS_SET, @@ -244,6 +278,7 @@ enum { NFSD_CMD_UNLOCK_IP, NFSD_CMD_UNLOCK_FILESYSTEM, NFSD_CMD_UNLOCK_EXPORT, + NFSD_CMD_SERVER_STATS_GET, __NFSD_CMD_MAX, NFSD_CMD_MAX = (__NFSD_CMD_MAX - 1) -- cgit From 46db3c8a1be96a354758b44b1d4fbb4b70d09a20 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Fri, 17 Jul 2026 07:08:58 -0400 Subject: nfsd: export NFSv4 callback op stats via netlink Add a proc4cb-ops nested attribute to the server-stats netlink dump, reusing the existing server-proc-entry (op/count) layout. The dump gains a callback section that emits one entry per callback opcode (OP_CB_GETATTR..OP_CB_OFFLOAD) from the per-netns callback counters, paged across messages like the other per-operation sections. This lets nfsstat report NFSv4 backchannel operation counts over netlink, including CB_GETATTR which corresponds to the procfs wdeleg_getattr line. Assisted-by: LLM Signed-off-by: Jeff Layton Link: https://patch.msgid.link/20260717-exportd-netlink-v7-6-b7ce17b83b60@kernel.org Signed-off-by: Chuck Lever --- Documentation/netlink/specs/nfsd.yaml | 6 ++++++ fs/nfsd/nfsctl.c | 27 +++++++++++++++++++++++++++ include/uapi/linux/nfsd_netlink.h | 1 + 3 files changed, 34 insertions(+) (limited to 'include/uapi') diff --git a/Documentation/netlink/specs/nfsd.yaml b/Documentation/netlink/specs/nfsd.yaml index 2a89d355ee7b..642268819c6f 100644 --- a/Documentation/netlink/specs/nfsd.yaml +++ b/Documentation/netlink/specs/nfsd.yaml @@ -410,6 +410,11 @@ attribute-sets: type: nest nested-attributes: server-proc-entry multi-attr: true + - + name: proc4cb-ops + type: nest + nested-attributes: server-proc-entry + multi-attr: true operations: list: @@ -621,6 +626,7 @@ operations: - proc3-ops - proc4-ops - proc4ops-ops + - proc4cb-ops mcast-groups: list: diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 93e18426039d..adb032b7311a 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -2451,6 +2451,29 @@ static int nfsd_nl_server_stats_nfs4ops(struct sk_buff *skb, return 0; } + +/* + * Emit NFSv4 callback (backchannel) per-operation counts, resuming at *idx, + * which counts from OP_CB_GETATTR. Same return convention as + * nfsd_nl_server_stats_proc(). + */ +static int nfsd_nl_server_stats_cbops(struct sk_buff *skb, + struct nfsd_net *nn, int *idx) +{ + int op; + + for (op = OP_CB_GETATTR + *idx; op <= OP_CB_OFFLOAD; op++, (*idx)++) { + u64 cnt = percpu_counter_sum_positive(&nn->cb_counter[op]); + + if (!cnt) + continue; + if (nfsd_nl_put_proc_entry(skb, NFSD_A_SERVER_STATS_PROC4CB_OPS, + op, cnt)) + return -EMSGSIZE; + } + + return 0; +} #endif /* Sections of the server-stats dump, emitted in order across messages. */ @@ -2459,6 +2482,7 @@ enum { NFSD_SERVER_STATS_PROC2, NFSD_SERVER_STATS_PROC3, NFSD_SERVER_STATS_PROC4, + NFSD_SERVER_STATS_PROC4CB, NFSD_SERVER_STATS_PROC4OPS, NFSD_SERVER_STATS_DONE, }; @@ -2527,6 +2551,9 @@ int nfsd_nl_server_stats_get_dumpit(struct sk_buff *skb, NFSD_A_SERVER_STATS_PROC4_OPS, &idx); break; #ifdef CONFIG_NFSD_V4 + case NFSD_SERVER_STATS_PROC4CB: + ret = nfsd_nl_server_stats_cbops(skb, nn, &idx); + break; case NFSD_SERVER_STATS_PROC4OPS: ret = nfsd_nl_server_stats_nfs4ops(skb, nn, &idx); break; diff --git a/include/uapi/linux/nfsd_netlink.h b/include/uapi/linux/nfsd_netlink.h index 3d076d173b1d..87da1d0bb21e 100644 --- a/include/uapi/linux/nfsd_netlink.h +++ b/include/uapi/linux/nfsd_netlink.h @@ -254,6 +254,7 @@ enum { NFSD_A_SERVER_STATS_PROC3_OPS, NFSD_A_SERVER_STATS_PROC4_OPS, NFSD_A_SERVER_STATS_PROC4OPS_OPS, + NFSD_A_SERVER_STATS_PROC4CB_OPS, __NFSD_A_SERVER_STATS_MAX, NFSD_A_SERVER_STATS_MAX = (__NFSD_A_SERVER_STATS_MAX - 1) -- cgit