> On Wed, Aug 30, 2023 at 03:05:46PM +0200, Lorenzo Bianconi wrote: > > Introduce rpc_status netlink support for NFSD in order to dump pending > > RPC requests debugging information from userspace. > > Very good to see this update! > > netdev has asked that all new netlink protocols start from a yaml > spec that resides under Documentation/netlink/specs/ That spec is > then used to generate netlink parser code for the kernel and for > user space tooling. You can find this all described here: > > https://docs.kernel.org/next/userspace-api/netlink/specs.html > > and here is a weak example of how this might be done: > > https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/net/handshake?id=3b3009ea8abb713b022d94fba95ec270cf6e7eae > > I say weak because I did that work while the yaml spec tools were > still under development. It might not completely reflect how this > needs to be done today. > > So the yaml file would be named something like: > > Documentation/netlink/specs/nfsd.yaml > > and it would generate files "fs/nfsd/netlink.[ch]". It should > generate a lot of the parser boiler plate you've written below > by hand, so just replace that code with calls to the generated > code. ack, I will look into it for v8 > > When you post the next revision of the series, cc: netdev. ack, will do. Regards, Lorenzo > > > > Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > > --- > > fs/nfsd/nfsctl.c | 275 +++++++++++++++++++++++++++++++++++++ > > fs/nfsd/nfsd.h | 19 +++ > > fs/nfsd/nfssvc.c | 15 ++ > > fs/nfsd/state.h | 2 - > > include/linux/sunrpc/svc.h | 1 + > > include/uapi/linux/nfs.h | 54 ++++++++ > > 6 files changed, 364 insertions(+), 2 deletions(-) > > > > diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > > index 33f80d289d63..4626a0002ceb 100644 > > --- a/fs/nfsd/nfsctl.c > > +++ b/fs/nfsd/nfsctl.c > > @@ -17,6 +17,9 @@ > > #include <linux/sunrpc/rpc_pipe_fs.h> > > #include <linux/module.h> > > #include <linux/fsnotify.h> > > +#include <net/genetlink.h> > > +#include <net/ip.h> > > +#include <net/ipv6.h> > > > > #include "idmap.h" > > #include "nfsd.h" > > @@ -1495,6 +1498,273 @@ static int create_proc_exports_entry(void) > > > > unsigned int nfsd_net_id; > > > > +/* the netlink family */ > > +static struct genl_family nfsd_genl; > > + > > +static const struct nla_policy > > +nfsd_rpc_status_compound_policy[NFS_ATTR_RPC_STATUS_COMPOUND_MAX + 1] = { > > + [NFS_ATTR_RPC_STATUS_COMPOUND_OP] = { .type = NLA_STRING }, > > +}; > > + > > +static const struct nla_policy > > +nfsd_rpc_status_policy[NFS_ATTR_RPC_STATUS_MAX + 1] = { > > + [NFS_ATTR_RPC_STATUS_XID] = { .type = NLA_U32 }, > > + [NFS_ATTR_RPC_STATUS_FLAGS] = { .type = NLA_U32 }, > > + [NFS_ATTR_RPC_STATUS_PC_NAME] = { .type = NLA_STRING }, > > + [NFS_ATTR_RPC_STATUS_VERSION] = { .type = NLA_U8 }, > > + [NFS_ATTR_RPC_STATUS_STIME] = { .type = NLA_S64 }, > > + [NFS_ATTR_RPC_STATUS_SADDR4] = { .len = sizeof_field(struct iphdr, saddr) }, > > + [NFS_ATTR_RPC_STATUS_DADDR4] = { .len = sizeof_field(struct iphdr, daddr) }, > > + [NFS_ATTR_RPC_STATUS_SADDR6] = { .len = sizeof_field(struct ipv6hdr, saddr) }, > > + [NFS_ATTR_RPC_STATUS_DADDR6] = { .len = sizeof_field(struct ipv6hdr, daddr) }, > > + [NFS_ATTR_RPC_STATUS_SPORT] = { .type = NLA_U16 }, > > + [NFS_ATTR_RPC_STATUS_DPORT] = { .type = NLA_U16 }, > > + [NFS_ATTR_RPC_STATUS_COMPOUND] = > > + NLA_POLICY_NESTED_ARRAY(nfsd_rpc_status_compound_policy), > > +}; > > + > > +static const struct nla_policy > > +nfsd_genl_policy[NFS_ATTR_MAX + 1] = { > > + [NFS_ATTR_RPC_STATUS] = NLA_POLICY_NESTED_ARRAY(nfsd_rpc_status_policy), > > +}; > > + > > +static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb, int index, > > + struct nfsd_genl_rqstp *rqstp) > > +{ > > + struct nlattr *rq_attr, *comp_attr; > > + int i; > > + > > + rq_attr = nla_nest_start(skb, index); > > + if (!rq_attr) > > + return -ENOBUFS; > > + > > + if (nla_put_be32(skb, NFS_ATTR_RPC_STATUS_XID, rqstp->rq_xid) || > > + nla_put_u32(skb, NFS_ATTR_RPC_STATUS_FLAGS, rqstp->rq_flags) || > > + nla_put_string(skb, NFS_ATTR_RPC_STATUS_PC_NAME, rqstp->pc_name) || > > + nla_put_u8(skb, NFS_ATTR_RPC_STATUS_VERSION, rqstp->rq_vers) || > > + nla_put_s64(skb, NFS_ATTR_RPC_STATUS_STIME, > > + ktime_to_us(rqstp->rq_stime), NFS_ATTR_RPC_STATUS_PAD)) > > + return -ENOBUFS; > > + > > + switch (rqstp->saddr.sa_family) { > > + case AF_INET: { > > + const struct sockaddr_in *s_in, *d_in; > > + > > + s_in = (const struct sockaddr_in *)&rqstp->saddr; > > + d_in = (const struct sockaddr_in *)&rqstp->daddr; > > + if (nla_put_in_addr(skb, NFS_ATTR_RPC_STATUS_SADDR4, > > + s_in->sin_addr.s_addr) || > > + nla_put_in_addr(skb, NFS_ATTR_RPC_STATUS_DADDR4, > > + d_in->sin_addr.s_addr) || > > + nla_put_be16(skb, NFS_ATTR_RPC_STATUS_SPORT, > > + s_in->sin_port) || > > + nla_put_be16(skb, NFS_ATTR_RPC_STATUS_DPORT, > > + d_in->sin_port)) > > + return -ENOBUFS; > > + break; > > + } > > + case AF_INET6: { > > + const struct sockaddr_in6 *s_in, *d_in; > > + > > + s_in = (const struct sockaddr_in6 *)&rqstp->saddr; > > + d_in = (const struct sockaddr_in6 *)&rqstp->daddr; > > + if (nla_put_in6_addr(skb, NFS_ATTR_RPC_STATUS_SADDR6, > > + &s_in->sin6_addr) || > > + nla_put_in6_addr(skb, NFS_ATTR_RPC_STATUS_DADDR6, > > + &d_in->sin6_addr) || > > + nla_put_be16(skb, NFS_ATTR_RPC_STATUS_SPORT, > > + s_in->sin6_port) || > > + nla_put_be16(skb, NFS_ATTR_RPC_STATUS_DPORT, > > + d_in->sin6_port)) > > + return -ENOBUFS; > > + break; > > + } > > + default: > > + break; > > + } > > + > > + comp_attr = nla_nest_start(skb, NFS_ATTR_RPC_STATUS_COMPOUND); > > + if (!comp_attr) > > + return -ENOBUFS; > > + > > + for (i = 0; i < rqstp->opcnt; i++) { > > + struct nlattr *op_attr; > > + > > + op_attr = nla_nest_start(skb, i); > > + if (!op_attr) > > + return -ENOBUFS; > > + > > + if (nla_put_string(skb, NFS_ATTR_RPC_STATUS_COMPOUND_OP, > > + nfsd4_op_name(rqstp->opnum[i]))) > > + return -ENOBUFS; > > + > > + nla_nest_end(skb, op_attr); > > + } > > + > > + nla_nest_end(skb, comp_attr); > > + nla_nest_end(skb, rq_attr); > > + > > + return 0; > > +} > > + > > +static int nfsd_genl_get_rpc_status(struct sk_buff *skb, struct genl_info *info) > > +{ > > + struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id); > > + struct nlattr *rpc_attr; > > + int i, rqstp_index = 0; > > + struct sk_buff *msg; > > + void *hdr; > > + > > + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); > > + if (!msg) > > + return -ENOMEM; > > + > > + hdr = genlmsg_put(msg, info->snd_portid, info->snd_seq, &nfsd_genl, > > + 0, NFS_CMD_NEW_RPC_STATUS); > > + if (!hdr) { > > + nlmsg_free(msg); > > + return -ENOBUFS; > > + } > > + > > + rpc_attr = nla_nest_start(msg, NFS_ATTR_RPC_STATUS); > > + if (!rpc_attr) > > + goto nla_put_failure; > > + > > + rcu_read_lock(); > > + > > + for (i = 0; i < nn->nfsd_serv->sv_nrpools; i++) { > > + struct svc_rqst *rqstp; > > + > > + list_for_each_entry_rcu(rqstp, > > + &nn->nfsd_serv->sv_pools[i].sp_all_threads, > > + rq_all) { > > + struct nfsd_genl_rqstp genl_rqstp; > > + unsigned int status_counter; > > + > > + /* > > + * Acquire rq_status_counter before parsing the rqst > > + * fields. rq_status_counter is set to an odd value in > > + * order to notify the consumers the rqstp fields are > > + * meaningful. > > + */ > > + status_counter = > > + smp_load_acquire(&rqstp->rq_status_counter); > > + if (!(status_counter & 1)) > > + continue; > > + > > + genl_rqstp.rq_xid = rqstp->rq_xid; > > + genl_rqstp.rq_flags = rqstp->rq_flags; > > + genl_rqstp.rq_vers = rqstp->rq_vers; > > + genl_rqstp.pc_name = svc_proc_name(rqstp); > > + genl_rqstp.rq_stime = rqstp->rq_stime; > > + genl_rqstp.opcnt = 0; > > + memcpy(&genl_rqstp.daddr, svc_daddr(rqstp), > > + sizeof(struct sockaddr)); > > + memcpy(&genl_rqstp.saddr, svc_addr(rqstp), > > + sizeof(struct sockaddr)); > > + > > +#ifdef CONFIG_NFSD_V4 > > + if (rqstp->rq_vers == NFS4_VERSION && > > + rqstp->rq_proc == NFSPROC4_COMPOUND) { > > + /* NFSv4 compund */ > > + struct nfsd4_compoundargs *args; > > + int j; > > + > > + args = rqstp->rq_argp; > > + genl_rqstp.opcnt = args->opcnt; > > + for (j = 0; j < genl_rqstp.opcnt; j++) > > + genl_rqstp.opnum[j] = > > + args->ops[j].opnum; > > + } > > +#endif /* CONFIG_NFSD_V4 */ > > + > > + /* > > + * Acquire rq_status_counter before reporting the rqst > > + * fields to the user. > > + */ > > + if (smp_load_acquire(&rqstp->rq_status_counter) != > > + status_counter) > > + continue; > > + > > + if (nfsd_genl_rpc_status_compose_msg(msg, > > + rqstp_index++, > > + &genl_rqstp)) > > + goto nla_put_failure_rcu; > > + } > > + } > > + > > + rcu_read_unlock(); > > + > > + nla_nest_end(msg, rpc_attr); > > + genlmsg_end(msg, hdr); > > + > > + return genlmsg_reply(msg, info); > > + > > +nla_put_failure_rcu: > > + rcu_read_unlock(); > > +nla_put_failure: > > + genlmsg_cancel(msg, hdr); > > + nlmsg_free(msg); > > + > > + return -EMSGSIZE; > > +} > > + > > +static int nfsd_genl_pre_doit(const struct genl_split_ops *ops, > > + struct sk_buff *skb, struct genl_info *info) > > +{ > > + struct nfsd_net *nn = net_generic(genl_info_net(info), nfsd_net_id); > > + > > + if (ops->internal_flags & NFSD_FLAG_NEED_REF_COUNT) { > > + int ret = -ENODEV; > > + > > + mutex_lock(&nfsd_mutex); > > + if (nn->nfsd_serv) { > > + svc_get(nn->nfsd_serv); > > + ret = 0; > > + } > > + mutex_unlock(&nfsd_mutex); > > + > > + return ret; > > + } > > + > > + return 0; > > +} > > + > > +static void nfsd_genl_post_doit(const struct genl_split_ops *ops, > > + struct sk_buff *skb, struct genl_info *info) > > +{ > > + if (ops->internal_flags & NFSD_FLAG_NEED_REF_COUNT) { > > + mutex_lock(&nfsd_mutex); > > + nfsd_put(genl_info_net(info)); > > + mutex_unlock(&nfsd_mutex); > > + } > > +} > > + > > +static struct genl_small_ops nfsd_genl_ops[] = { > > + { > > + .cmd = NFS_CMD_GET_RPC_STATUS, > > + .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, > > + .doit = nfsd_genl_get_rpc_status, > > + .internal_flags = NFSD_FLAG_NEED_REF_COUNT, > > + }, > > +}; > > + > > +static struct genl_family nfsd_genl __ro_after_init = { > > + .name = "nfsd_server", > > + .version = 1, > > + .maxattr = NFS_ATTR_MAX, > > + .module = THIS_MODULE, > > + .netnsok = true, > > + .parallel_ops = true, > > + .hdrsize = 0, > > + .pre_doit = nfsd_genl_pre_doit, > > + .post_doit = nfsd_genl_post_doit, > > + .policy = nfsd_genl_policy, > > + .small_ops = nfsd_genl_ops, > > + .n_small_ops = ARRAY_SIZE(nfsd_genl_ops), > > + .resv_start_op = NFS_CMD_NEW_RPC_STATUS + 1, > > +}; > > + > > /** > > * nfsd_net_init - Prepare the nfsd_net portion of a new net namespace > > * @net: a freshly-created network namespace > > @@ -1589,6 +1859,10 @@ static int __init init_nfsd(void) > > retval = register_filesystem(&nfsd_fs_type); > > if (retval) > > goto out_free_all; > > + retval = genl_register_family(&nfsd_genl); > > + if (retval) > > + goto out_free_all; > > + > > return 0; > > out_free_all: > > nfsd4_destroy_laundry_wq(); > > @@ -1613,6 +1887,7 @@ static int __init init_nfsd(void) > > > > static void __exit exit_nfsd(void) > > { > > + genl_unregister_family(&nfsd_genl); > > unregister_filesystem(&nfsd_fs_type); > > nfsd4_destroy_laundry_wq(); > > unregister_cld_notifier(); > > diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > > index e95c3322eb9b..749c871b3291 100644 > > --- a/fs/nfsd/nfsd.h > > +++ b/fs/nfsd/nfsd.h > > @@ -62,6 +62,25 @@ struct readdir_cd { > > __be32 err; /* 0, nfserr, or nfserr_eof */ > > }; > > > > +enum nfsd_genl_internal_flag { > > + NFSD_FLAG_NEED_REF_COUNT = BIT(0), > > +}; > > + > > +/* Maximum number of operations per session compound */ > > +#define NFSD_MAX_OPS_PER_COMPOUND 50 > > + > > +struct nfsd_genl_rqstp { > > + struct sockaddr daddr; > > + struct sockaddr saddr; > > + unsigned long rq_flags; > > + const char *pc_name; > > + ktime_t rq_stime; > > + __be32 rq_xid; > > + u32 rq_vers; > > + /* NFSv4 compund */ > > + u32 opnum[NFSD_MAX_OPS_PER_COMPOUND]; > > + u16 opcnt; > > +}; > > > > extern struct svc_program nfsd_program; > > extern const struct svc_version nfsd_version2, nfsd_version3, nfsd_version4; > > diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c > > index 1582af33e204..fad34a7325b3 100644 > > --- a/fs/nfsd/nfssvc.c > > +++ b/fs/nfsd/nfssvc.c > > @@ -998,6 +998,15 @@ int nfsd_dispatch(struct svc_rqst *rqstp) > > if (!proc->pc_decode(rqstp, &rqstp->rq_arg_stream)) > > goto out_decode_err; > > > > + /* > > + * Release rq_status_counter setting it to an odd value after the rpc > > + * request has been properly parsed. rq_status_counter is used to > > + * notify the consumers if the rqstp fields are stable > > + * (rq_status_counter is odd) or not meaningful (rq_status_counter > > + * is even). > > + */ > > + smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter | 1); > > + > > rp = NULL; > > switch (nfsd_cache_lookup(rqstp, &rp)) { > > case RC_DOIT: > > @@ -1015,6 +1024,12 @@ int nfsd_dispatch(struct svc_rqst *rqstp) > > if (!proc->pc_encode(rqstp, &rqstp->rq_res_stream)) > > goto out_encode_err; > > > > + /* > > + * Release rq_status_counter setting it to an even value after the rpc > > + * request has been properly processed. > > + */ > > + smp_store_release(&rqstp->rq_status_counter, rqstp->rq_status_counter + 1); > > + > > nfsd_cache_update(rqstp, rp, rqstp->rq_cachetype, statp + 1); > > out_cached_reply: > > return 1; > > diff --git a/fs/nfsd/state.h b/fs/nfsd/state.h > > index cbddcf484dba..41bdc913fa71 100644 > > --- a/fs/nfsd/state.h > > +++ b/fs/nfsd/state.h > > @@ -174,8 +174,6 @@ static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s) > > > > /* Maximum number of slots per session. 160 is useful for long haul TCP */ > > #define NFSD_MAX_SLOTS_PER_SESSION 160 > > -/* Maximum number of operations per session compound */ > > -#define NFSD_MAX_OPS_PER_COMPOUND 50 > > /* Maximum session per slot cache size */ > > #define NFSD_SLOT_CACHE_SIZE 2048 > > /* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */ > > diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h > > index dbf5b21feafe..caa20defd255 100644 > > --- a/include/linux/sunrpc/svc.h > > +++ b/include/linux/sunrpc/svc.h > > @@ -251,6 +251,7 @@ struct svc_rqst { > > * net namespace > > */ > > void ** rq_lease_breaker; /* The v4 client breaking a lease */ > > + unsigned int rq_status_counter; /* RPC processing counter */ > > }; > > > > /* bits for rq_flags */ > > diff --git a/include/uapi/linux/nfs.h b/include/uapi/linux/nfs.h > > index 946cb62d64b0..86a5daaaf9d9 100644 > > --- a/include/uapi/linux/nfs.h > > +++ b/include/uapi/linux/nfs.h > > @@ -132,4 +132,58 @@ enum nfs_ftype { > > NFFIFO = 8 > > }; > > > > +enum nfs_commands { > > + NFS_CMD_UNSPEC, > > + > > + NFS_CMD_GET_RPC_STATUS, > > + NFS_CMD_NEW_RPC_STATUS, > > + > > + /* add new commands above here */ > > + > > + __NFS_CMD_MAX, > > + NFS_CMD_MAX = __NFS_CMD_MAX - 1, > > +}; > > + > > +enum nfs_rcp_status_compound_attrs { > > + __NFS_ATTR_RPC_STATUS_COMPOUND_UNSPEC, > > + NFS_ATTR_RPC_STATUS_COMPOUND_OP, > > + > > + /* keep it last */ > > + NUM_NFS_ATTR_RPC_STATUS_COMPOUND, > > + NFS_ATTR_RPC_STATUS_COMPOUND_MAX = NUM_NFS_ATTR_RPC_STATUS_COMPOUND - 1, > > +}; > > + > > +enum nfs_rpc_status_attrs { > > + __NFS_ATTR_RPC_STATUS_UNSPEC, > > + > > + NFS_ATTR_RPC_STATUS_XID, > > + NFS_ATTR_RPC_STATUS_FLAGS, > > + NFS_ATTR_RPC_STATUS_PC_NAME, > > + NFS_ATTR_RPC_STATUS_VERSION, > > + NFS_ATTR_RPC_STATUS_STIME, > > + NFS_ATTR_RPC_STATUS_SADDR4, > > + NFS_ATTR_RPC_STATUS_DADDR4, > > + NFS_ATTR_RPC_STATUS_SADDR6, > > + NFS_ATTR_RPC_STATUS_DADDR6, > > + NFS_ATTR_RPC_STATUS_SPORT, > > + NFS_ATTR_RPC_STATUS_DPORT, > > + NFS_ATTR_RPC_STATUS_PAD, > > + NFS_ATTR_RPC_STATUS_COMPOUND, > > + > > + /* keep it last */ > > + NUM_NFS_ATTR_RPC_STATUS, > > + NFS_ATTR_RPC_STATUS_MAX = NUM_NFS_ATTR_RPC_STATUS - 1, > > +}; > > + > > +enum nfs_attrs { > > + NFS_ATTR_UNSPEC, > > + > > + NFS_ATTR_RPC_STATUS, > > + > > + /* add new attributes above here */ > > + > > + __NFS_ATTR_MAX, > > + NFS_ATTR_MAX = __NFS_ATTR_MAX - 1 > > +}; > > + > > #endif /* _UAPI_LINUX_NFS_H */ > > -- > > 2.41.0 > > > > -- > Chuck Lever >
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