> > > > On Aug 10, 2023, at 4:24 PM, NeilBrown <neilb@xxxxxxx> wrote: > > > > On Fri, 11 Aug 2023, Chuck Lever wrote: > >> On Thu, Aug 10, 2023 at 10:39:21AM +0200, Lorenzo Bianconi wrote: > >>> Introduce rpc_status entry in nfsd debug filesystem in order to dump > >>> pending RPC requests debugging information. > >>> > >>> Link: https://bugzilla.linux-nfs.org/show_bug.cgi?id=366 > >>> Reviewed-by: NeilBrown <neilb@xxxxxxx> > >>> Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx> > >>> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> > >>> --- > >>> fs/nfsd/nfs4proc.c | 4 +- > >>> fs/nfsd/nfsctl.c | 9 +++ > >>> fs/nfsd/nfsd.h | 7 ++ > >>> fs/nfsd/nfssvc.c | 140 +++++++++++++++++++++++++++++++++++++ > >>> include/linux/sunrpc/svc.h | 1 + > >>> net/sunrpc/svc.c | 2 +- > >>> 6 files changed, 159 insertions(+), 4 deletions(-) > >>> > >>> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c > >>> index aa4f21f92deb..ff5a1dddc0ed 100644 > >>> --- a/fs/nfsd/nfs4proc.c > >>> +++ b/fs/nfsd/nfs4proc.c > >>> @@ -2496,8 +2496,6 @@ static inline void nfsd4_increment_op_stats(u32 opnum) > >>> > >>> static const struct nfsd4_operation nfsd4_ops[]; > >>> > >>> -static const char *nfsd4_op_name(unsigned opnum); > >>> - > >>> /* > >>> * Enforce NFSv4.1 COMPOUND ordering rules: > >>> * > >>> @@ -3627,7 +3625,7 @@ void warn_on_nonidempotent_op(struct nfsd4_op *op) > >>> } > >>> } > >>> > >>> -static const char *nfsd4_op_name(unsigned opnum) > >>> +const char *nfsd4_op_name(unsigned int opnum) > >>> { > >>> if (opnum < ARRAY_SIZE(nfsd4_ops)) > >>> return nfsd4_ops[opnum].op_name; > >>> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > >>> index dad88bff3b9e..83eb5c6d894e 100644 > >>> --- a/fs/nfsd/nfsctl.c > >>> +++ b/fs/nfsd/nfsctl.c > >>> @@ -47,6 +47,7 @@ enum { > >>> NFSD_MaxBlkSize, > >>> NFSD_MaxConnections, > >>> NFSD_Filecache, > >>> + NFSD_Rpc_Status, > >>> /* > >>> * The below MUST come last. Otherwise we leave a hole in nfsd_files[] > >>> * with !CONFIG_NFSD_V4 and simple_fill_super() goes oops > >>> @@ -195,6 +196,13 @@ static inline struct net *netns(struct file *file) > >>> return file_inode(file)->i_sb->s_fs_info; > >>> } > >>> > >>> +static const struct file_operations nfsd_rpc_status_operations = { > >>> + .open = nfsd_rpc_status_open, > >>> + .read = seq_read, > >>> + .llseek = seq_lseek, > >>> + .release = nfsd_stats_release, > >>> +}; > >>> + > >>> /* > >>> * write_unlock_ip - Release all locks used by a client > >>> * > >>> @@ -1394,6 +1402,7 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc) > >>> [NFSD_MaxBlkSize] = {"max_block_size", &transaction_ops, S_IWUSR|S_IRUGO}, > >>> [NFSD_MaxConnections] = {"max_connections", &transaction_ops, S_IWUSR|S_IRUGO}, > >>> [NFSD_Filecache] = {"filecache", &nfsd_file_cache_stats_fops, S_IRUGO}, > >>> + [NFSD_Rpc_Status] = {"rpc_status", &nfsd_rpc_status_operations, S_IRUGO}, > >>> #ifdef CONFIG_NFSD_V4 > >>> [NFSD_Leasetime] = {"nfsv4leasetime", &transaction_ops, S_IWUSR|S_IRUSR}, > >>> [NFSD_Gracetime] = {"nfsv4gracetime", &transaction_ops, S_IWUSR|S_IRUSR}, > >>> diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h > >>> index 55b9d85ed71b..3e8a47b93fd4 100644 > >>> --- a/fs/nfsd/nfsd.h > >>> +++ b/fs/nfsd/nfsd.h > >>> @@ -94,6 +94,7 @@ int nfsd_get_nrthreads(int n, int *, struct net *); > >>> int nfsd_set_nrthreads(int n, int *, struct net *); > >>> int nfsd_pool_stats_open(struct inode *, struct file *); > >>> int nfsd_stats_release(struct inode *, struct file *); > >>> +int nfsd_rpc_status_open(struct inode *inode, struct file *file); > >>> void nfsd_shutdown_threads(struct net *net); > >>> > >>> static inline void nfsd_put(struct net *net) > >>> @@ -511,12 +512,18 @@ extern void nfsd4_ssc_init_umount_work(struct nfsd_net *nn); > >>> > >>> extern void nfsd4_init_leases_net(struct nfsd_net *nn); > >>> > >>> +const char *nfsd4_op_name(unsigned int opnum); > >>> #else /* CONFIG_NFSD_V4 */ > >>> static inline int nfsd4_is_junction(struct dentry *dentry) > >>> { > >>> return 0; > >>> } > >>> > >>> +static inline const char *nfsd4_op_name(unsigned int opnum) > >>> +{ > >>> + return "unknown_operation"; > >>> +} > >>> + > >>> static inline void nfsd4_init_leases_net(struct nfsd_net *nn) { }; > >>> > >>> #define register_cld_notifier() 0 > >>> diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c > >>> index 460219030ce1..237be14d3a11 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; > >>> @@ -1101,3 +1116,128 @@ int nfsd_stats_release(struct inode *inode, struct file *file) > >>> mutex_unlock(&nfsd_mutex); > >>> return ret; > >>> } > >>> + > >>> +static int nfsd_rpc_status_show(struct seq_file *m, void *v) > >>> +{ > >>> + struct inode *inode = file_inode(m->file); > >>> + struct nfsd_net *nn = net_generic(inode->i_sb->s_fs_info, nfsd_net_id); > >>> + int i; > >>> + > >>> + seq_puts(m, "# XID FLAGS VERS PROC TIMESTAMP SADDR SPORT DADDR DPORT COMPOUND_OPS\n"); > >>> + > >>> + 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 { > >>> + 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]; > >>> + } rqstp_info; > >>> + unsigned int status_counter; > >>> + char buf[RPC_MAX_ADDRBUFLEN]; > >>> + int opcnt = 0; > >>> + > >>> + /* > >>> + * 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; > >>> + > >>> + rqstp_info.rq_xid = rqstp->rq_xid; > >>> + rqstp_info.rq_flags = rqstp->rq_flags; > >>> + rqstp_info.rq_vers = rqstp->rq_vers; > >>> + rqstp_info.pc_name = svc_proc_name(rqstp); > >>> + rqstp_info.rq_stime = rqstp->rq_stime; > >>> + memcpy(&rqstp_info.daddr, svc_daddr(rqstp), > >>> + sizeof(struct sockaddr)); > >>> + memcpy(&rqstp_info.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 = rqstp->rq_argp; > >>> + int j; > >>> + > >>> + opcnt = args->opcnt; > >>> + for (j = 0; j < opcnt; j++) { > >>> + struct nfsd4_op *op = &args->ops[j]; > >>> + > >>> + rqstp_info.opnum[j] = op->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; > >>> + > >>> + seq_printf(m, > >>> + "%04u %04ld NFSv%d %s %016lld", > >>> + be32_to_cpu(rqstp_info.rq_xid), > >> > >> It's proper to display XIDs as 8-hexit hexadecimal values, as you > >> did before. "0x%08x" is the correct format, as that matches the > >> XID display format used by Wireshark and our tracepoints. > >> > >> > >>> + rqstp_info.rq_flags, > >> > >> I didn't mean for you to change the flags format to decimal. I was > >> trying to point out that the content of this field will need to be > >> displayed symbolically if we care about an easy user experience. > >> > >> Let's stick with hex here. A clever user can read the bits directly > >> from that. All others should have a tool that parses this field and > >> prints the list of bits in it symbolically. > >> > >> > >>> + rqstp_info.rq_vers, > >>> + rqstp_info.pc_name, > >>> + ktime_to_us(rqstp_info.rq_stime)); > >>> + seq_printf(m, " %s", > >>> + __svc_print_addr(&rqstp_info.saddr, buf, > >>> + sizeof(buf), false)); > >>> + seq_printf(m, " %s", > >>> + __svc_print_addr(&rqstp_info.daddr, buf, > >>> + sizeof(buf), false)); > >>> + if (opcnt) { > >>> + int j; > >>> + > >>> + seq_puts(m, " "); > >>> + for (j = 0; j < opcnt; j++) > >>> + seq_printf(m, "%s%s", > >>> + nfsd4_op_name(rqstp_info.opnum[j]), > >>> + j == opcnt - 1 ? "" : ":"); > >>> + } else { > >>> + seq_puts(m, " -"); > >>> + } > >> > >> This looks correct to me. > >> > >> I'm leaning towards moving this to a netlink API that can be > >> extended over time to handle other stats and also act as an NFSD > >> control plane, similar to other network subsystems. > >> > >> Any comments, complaints or rotten fruit from anyone? > > > > I think netlink is the best way forward. 'cat' is nice, but not > > necessary. We have an established path for distributing tools for > > working with nfsd so we get easily get a suitable tool into the hands of > > our users. > > > > The only fruit I have relates to the name "rpc_status", and it probably > > over-ripe rather than rotten :-) > > In the context of RPC, "status" means the success/failure result of a > > request. That is not what this file provides. It is a list of active > > requests. So maybe "active_rpc". > > One advantage of netlink is that the API is based on numbers, not names! > > There won't be a file name with netlink, so right, it won't be an > issue. > > Lorenzo, can you proceed with netlink instead of /proc/fs/nfsd? > Maybe start with a yaml spec file? ack, I will start working on it soon. Regards, Lorenzo > > > > NeilBrown > > > > > >> > >> > >>> + seq_puts(m, "\n"); > >>> + } > >>> + } > >>> + > >>> + rcu_read_unlock(); > >>> + > >>> + return 0; > >>> +} > >>> + > >>> +/** > >>> + * nfsd_rpc_status_open - open routine for nfsd_rpc_status handler > >>> + * @inode: entry inode pointer. > >>> + * @file: entry file pointer. > >>> + * > >>> + * nfsd_rpc_status_open is the open routine for nfsd_rpc_status procfs handler. > >>> + * nfsd_rpc_status dumps pending RPC requests info queued into nfs server. > >>> + */ > >>> +int nfsd_rpc_status_open(struct inode *inode, struct file *file) > >>> +{ > >>> + int ret = nfsd_stats_open(inode); > >>> + > >>> + if (ret) > >>> + return ret; > >>> + > >>> + return single_open(file, nfsd_rpc_status_show, inode->i_private); > >>> +} > >>> diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h > >>> index 7838b37bcfa8..b49c0470b4fe 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/net/sunrpc/svc.c b/net/sunrpc/svc.c > >>> index af692bff44ab..83bee19df104 100644 > >>> --- a/net/sunrpc/svc.c > >>> +++ b/net/sunrpc/svc.c > >>> @@ -1656,7 +1656,7 @@ const char *svc_proc_name(const struct svc_rqst *rqstp) > >>> return rqstp->rq_procinfo->pc_name; > >>> return "unknown"; > >>> } > >>> - > >>> +EXPORT_SYMBOL_GPL(svc_proc_name); > >>> > >>> /** > >>> * svc_encode_result_payload - mark a range of bytes as a result payload > >>> -- > >>> 2.41.0 > >>> > >> > >> -- > >> Chuck Lever > >> > > > > -- > Chuck Lever > >
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