Re: [RFC] NFSD: add rpc_status entry in nfsd debug filesystem
From: Chuck Lever <cel@kernel.org>
Date: 2023-06-29 13:55:43
On Thu, Jun 29, 2023 at 12:17:33PM +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
Nice to see progress on this. Do you have a user space tool to monitor this file?
quoted hunk ↗ jump to hunk
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- fs/nfsd/nfs4proc.c | 4 +-- fs/nfsd/nfsctl.c | 18 ++++++++++++++ fs/nfsd/nfsd.h | 2 ++ fs/nfsd/nfssvc.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++ net/sunrpc/svc.c | 2 +- 5 files changed, 83 insertions(+), 4 deletions(-)diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 5ae670807449..a4dd1ef104c3 100644 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c@@ -2452,8 +2452,6 @@ 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: *@@ -3583,7 +3581,7 @@ void warn_on_nonidempotent_op(struct nfsd4_op *op) } } -static const char *nfsd4_op_name(unsigned opnum) +const char *nfsd4_op_name(unsigned 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 1489e0b703b4..9d0b0a53510b 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c@@ -57,6 +57,8 @@ enum { NFSD_RecoveryDir, NFSD_V4EndGrace, #endif + NFSD_Rpc_Status, + NFSD_MaxReserved };@@ -195,6 +197,21 @@ static inline struct net *netns(struct file *file) return file_inode(file)->i_sb->s_fs_info; } +static int nfsd_rpc_status_show(struct seq_file *m, void *v) +{ + struct nfsd_net *nn = net_generic(file_inode(m->file)->i_sb->s_fs_info, + nfsd_net_id); + + mutex_lock(&nfsd_mutex); + if (nn->nfsd_serv) + nsfd_rpc_status(m, nn->nfsd_serv); + mutex_unlock(&nfsd_mutex); + + return 0; +} + +DEFINE_SHOW_ATTRIBUTE(nfsd_rpc_status); + /* * write_unlock_ip - Release all locks used by a client *@@ -1400,6 +1417,7 @@ static int nfsd_fill_super(struct super_block *sb, struct fs_context *fc) [NFSD_RecoveryDir] = {"nfsv4recoverydir", &transaction_ops, S_IWUSR|S_IRUSR}, [NFSD_V4EndGrace] = {"v4_end_grace", &transaction_ops, S_IWUSR|S_IRUGO}, #endif + [NFSD_Rpc_Status] = {"rpc_status", &nfsd_rpc_status_fops, S_IRUGO}, /* last one */ {""} };diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h index d88498f8b275..a149157ec243 100644 --- a/fs/nfsd/nfsd.h +++ b/fs/nfsd/nfsd.h@@ -87,6 +87,7 @@ bool nfssvc_encode_voidres(struct svc_rqst *rqstp, */ int nfsd_svc(int nrservs, struct net *net, const struct cred *cred); int nfsd_dispatch(struct svc_rqst *rqstp); +void nsfd_rpc_status(struct seq_file *m, struct svc_serv *serv); int nfsd_nrthreads(struct net *); int nfsd_nrpools(struct net *);@@ -506,6 +507,7 @@ 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 opnum); #else /* CONFIG_NFSD_V4 */ static inline int nfsd4_is_junction(struct dentry *dentry) {diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c index 9c7b1ef5be40..7a881f9a3a13 100644 --- a/fs/nfsd/nfssvc.c +++ b/fs/nfsd/nfssvc.c@@ -1142,3 +1142,64 @@ int nfsd_pool_stats_release(struct inode *inode, struct file *file) mutex_unlock(&nfsd_mutex); return ret; } +
Please add a kdoc comment here that describes the purpose of this function, its API contract, and any non-obvious assumptions.
+void nsfd_rpc_status(struct seq_file *m, struct svc_serv *serv)
+{
+ int i;
+
+ lockdep_assert_held(&nfsd_mutex);The nfsd_mutex is held, I assume, to serialize with service shutdown. IMO you should add a comment to that effect.
+ + rcu_read_lock();
The RCU read lock protects the sp_all_threads list. OK.
+
+ for (i = 0; i < serv->sv_nrpools; i++) {
+ struct svc_rqst *rqstp;
+
+ seq_puts(m, "XID | FLAGS | PROG |");
+ seq_puts(m, " VERS | PROC\t|");
+ seq_puts(m, " REMOTE - LOCAL IP ADDR");
+ seq_puts(m, "\t\t\t\t\t\t\t\t | NFS4 COMPOUND OPS\n");
+ list_for_each_entry_rcu(rqstp,
+ &serv->sv_pools[i].sp_all_threads,
+ rq_all) {
+ if (!test_bit(RQ_BUSY, &rqstp->rq_flags))
+ continue;
+
+ seq_printf(m,
+ "0x%08x | 0x%08lx | 0x%08x | NFSv%d | %s\t|",
+ be32_to_cpu(rqstp->rq_xid), rqstp->rq_flags,
+ rqstp->rq_prog, rqstp->rq_vers,
+ svc_proc_name(rqstp));
+
+ if (rqstp->rq_addr.ss_family == AF_INET) {
+ seq_printf(m, " %pI4 - %pI4\t\t\t\t\t\t\t |",
+ &((struct sockaddr_in *)&rqstp->rq_addr)->sin_addr,
+ &((struct sockaddr_in *)&rqstp->rq_daddr)->sin_addr);
+ } else if (rqstp->rq_addr.ss_family == AF_INET6) {
+ seq_printf(m, " %pI6 - %pI6 |",
+ &((struct sockaddr_in6 *)&rqstp->rq_addr)->sin6_addr,
+ &((struct sockaddr_in6 *)&rqstp->rq_daddr)->sin6_addr);
+ } else {
+ seq_printf(m, " Unknown address family: %hu\n",
+ rqstp->rq_addr.ss_family);
+ continue;
+ }
+#ifdef CONFIG_NFSD_V4
+ if (rqstp->rq_vers == NFS4_VERSION &&
+ rqstp->rq_proc == NFSPROC4_COMPOUND) {
+ /* NFSv4 compund */
+ struct nfsd4_compoundargs *args = rqstp->rq_argp;
+ struct nfsd4_compoundres *resp = rqstp->rq_resp;
+
+ while (resp->opcnt < args->opcnt) {
+ struct nfsd4_op *op = &args->ops[resp->opcnt++];
+
+ seq_printf(m, " %s", nfsd4_op_name(op->opnum));
+ }
+ }
+#endif /* CONFIG_NFSD_V4 */
+ seq_puts(m, "\n");My only quibble here is that the file format needs to be parsable by scripts as well as readable by humans. I'm not sure I have a specific comment, but it's something that needs some attention and verification (with, say, a sample user space tool, hint hint).
quoted hunk ↗ jump to hunk
+ } + } + + rcu_read_unlock(); +}diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c index e6d4cec61e47..f99cad92e9f4 100644 --- a/net/sunrpc/svc.c +++ b/net/sunrpc/svc.c@@ -1625,7 +1625,7 @@ 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