From bd9d6a3efa9709e653aafbeb859289feccb8e70c Mon Sep 17 00:00:00 2001
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: Mon, 11 Sep 2023 14:49:46 +0200
Subject: [PATCH] NFSD: add rpc_status netlink support
Introduce rpc_status netlink support for NFSD in order to dump pending
RPC requests debugging information from userspace.
Closes: https://bugzilla.linux-nfs.org/show_bug.cgi?id=366
Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
fs/nfsd/nfsctl.c | 188 ++++++++++++++++++++++++++++++++++++-
fs/nfsd/nfsd.h | 17 ++++
fs/nfsd/nfssvc.c | 15 +++
fs/nfsd/state.h | 2 -
include/linux/sunrpc/svc.h | 1 +
5 files changed, 220 insertions(+), 3 deletions(-)
diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 364ccd0be1c11..739ed5bf71cd0 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1496,19 +1496,200 @@ static int create_proc_exports_entry(void)
unsigned int nfsd_net_id;
+/**
+ * nfsd_nl_rpc_status_get_start - Prepare rpc_status_get dumpit
+ * @cb: netlink metadata and command arguments
+ *
+ * Return values:
+ * %0: The rpc_status_get command may proceed
+ * %-ENODEV: There is no NFSD running in this namespace
+ */
int nfsd_nl_rpc_status_get_start(struct netlink_callback *cb)
{
+ struct nfsd_net *nn = net_generic(sock_net(cb->skb->sk), nfsd_net_id);
+ int ret = -ENODEV;
+
+ mutex_lock(&nfsd_mutex);
+ if (nn->nfsd_serv) {
+ svc_get(nn->nfsd_serv);
+ ret = 0;
+ }
+ mutex_unlock(&nfsd_mutex);
+
+ return ret;
+}
+
+static int nfsd_genl_rpc_status_compose_msg(struct sk_buff *skb,
+ struct netlink_callback *cb,
+ struct nfsd_genl_rqstp *rqstp)
+{
+ void *hdr;
+ u32 i;
+
+ hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+ &nfsd_nl_family, 0, NFSD_CMD_RPC_STATUS_GET);
+ if (!hdr)
+ return -ENOBUFS;
+
+ if (nla_put_be32(skb, NFSD_A_RPC_STATUS_XID, rqstp->rq_xid) ||
+ nla_put_u32(skb, NFSD_A_RPC_STATUS_FLAGS, rqstp->rq_flags) ||
+ nla_put_u32(skb, NFSD_A_RPC_STATUS_PROG, rqstp->rq_prog) ||
+ nla_put_u32(skb, NFSD_A_RPC_STATUS_PROC, rqstp->rq_proc) ||
+ nla_put_u8(skb, NFSD_A_RPC_STATUS_VERSION, rqstp->rq_vers) ||
+ nla_put_s64(skb, NFSD_A_RPC_STATUS_SERVICE_TIME,
+ ktime_to_us(rqstp->rq_stime),
+ NFSD_A_RPC_STATUS_PAD))
+ return -ENOBUFS;
+
+ switch (rqstp->rq_saddr.sa_family) {
+ case AF_INET: {
+ const struct sockaddr_in *s_in, *d_in;
+
+ s_in = (const struct sockaddr_in *)&rqstp->rq_saddr;
+ d_in = (const struct sockaddr_in *)&rqstp->rq_daddr;
+ if (nla_put_in_addr(skb, NFSD_A_RPC_STATUS_SADDR4,
+ s_in->sin_addr.s_addr) ||
+ nla_put_in_addr(skb, NFSD_A_RPC_STATUS_DADDR4,
+ d_in->sin_addr.s_addr) ||
+ nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
+ s_in->sin_port) ||
+ nla_put_be16(skb, NFSD_A_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->rq_saddr;
+ d_in = (const struct sockaddr_in6 *)&rqstp->rq_daddr;
+ if (nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_SADDR6,
+ &s_in->sin6_addr) ||
+ nla_put_in6_addr(skb, NFSD_A_RPC_STATUS_DADDR6,
+ &d_in->sin6_addr) ||
+ nla_put_be16(skb, NFSD_A_RPC_STATUS_SPORT,
+ s_in->sin6_port) ||
+ nla_put_be16(skb, NFSD_A_RPC_STATUS_DPORT,
+ d_in->sin6_port))
+ return -ENOBUFS;
+ break;
+ }
+ }
+
+ for (i = 0; i < rqstp->rq_opcnt; i++)
+ if (nla_put_u32(skb, NFSD_A_RPC_STATUS_COMPOUND_OPS,
+ rqstp->rq_opnum[i]))
+ return -ENOBUFS;
+
+ genlmsg_end(skb, hdr);
return 0;
}
+/**
+ * nfsd_nl_rpc_status_get_dumpit - Handle rpc_status_get dumpit
+ * @skb: reply buffer
+ * @cb: netlink metadata and command arguments
+ *
+ * Returns the size of the reply or a negative errno.
+ */
int nfsd_nl_rpc_status_get_dumpit(struct sk_buff *skb,
struct netlink_callback *cb)
{
- return 0;
+ struct nfsd_net *nn = net_generic(sock_net(skb->sk), nfsd_net_id);
+ int i, ret, rqstp_index = 0;
+
+ rcu_read_lock();
+
+ for (i = 0; i < nn->nfsd_serv->sv_nrpools; i++) {
+ struct svc_rqst *rqstp;
+
+ if (i < cb->args[0]) /* already consumed */
+ continue;
+
+ rqstp_index = 0;
+ 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;
+
+ if (rqstp_index++ < cb->args[1]) /* already consumed */
+ continue;
+ /*
+ * 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.rq_prog = rqstp->rq_prog;
+ genl_rqstp.rq_proc = rqstp->rq_proc;
+ genl_rqstp.rq_stime = rqstp->rq_stime;
+ genl_rqstp.rq_opcnt = 0;
+ memcpy(&genl_rqstp.rq_daddr, svc_daddr(rqstp),
+ sizeof(struct sockaddr));
+ memcpy(&genl_rqstp.rq_saddr, svc_addr(rqstp),
+ sizeof(struct sockaddr));
+
+#ifdef CONFIG_NFSD_V4
+ if (rqstp->rq_vers == NFS4_VERSION &&
+ rqstp->rq_proc == NFSPROC4_COMPOUND) {
+ /* NFSv4 compound */
+ struct nfsd4_compoundargs *args;
+ int j;
+
+ args = rqstp->rq_argp;
+ genl_rqstp.rq_opcnt = args->opcnt;
+ for (j = 0; j < genl_rqstp.rq_opcnt; j++)
+ genl_rqstp.rq_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;
+
+ ret = nfsd_genl_rpc_status_compose_msg(skb, cb,
+ &genl_rqstp);
+ if (ret)
+ goto out;
+ }
+ }
+
+ cb->args[0] = i;
+ cb->args[1] = rqstp_index;
+ ret = skb->len;
+out:
+ rcu_read_unlock();
+
+ return ret;
}
+/**
+ * nfsd_nl_rpc_status_get_done - rpc_status_get dumpit post-processing
+ * @cb: netlink metadata and command arguments
+ *
+ * Return values:
+ * %0: Success
+ */
int nfsd_nl_rpc_status_get_done(struct netlink_callback *cb)
{
+ mutex_lock(&nfsd_mutex);
+ nfsd_put(sock_net(cb->skb->sk));
+ mutex_unlock(&nfsd_mutex);
+
return 0;
}
@@ -1606,6 +1787,10 @@ static int __init init_nfsd(void)
retval = register_filesystem(&nfsd_fs_type);
if (retval)
goto out_free_all;
+ retval = genl_register_family(&nfsd_nl_family);
+ if (retval)
+ goto out_free_all;
+
return 0;
out_free_all:
nfsd4_destroy_laundry_wq();
@@ -1630,6 +1815,7 @@ static int __init init_nfsd(void)
static void __exit exit_nfsd(void)
{
+ genl_unregister_family(&nfsd_nl_family);
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 11c14faa6c67b..f5ff42f41ee7f 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -62,6 +62,23 @@ struct readdir_cd {
__be32 err; /* 0, nfserr, or nfserr_eof */
};
+/* Maximum number of operations per session compound */
+#define NFSD_MAX_OPS_PER_COMPOUND 50
+
+struct nfsd_genl_rqstp {
+ struct sockaddr rq_daddr;
+ struct sockaddr rq_saddr;
+ unsigned long rq_flags;
+ ktime_t rq_stime;
+ __be32 rq_xid;
+ u32 rq_vers;
+ u32 rq_prog;
+ u32 rq_proc;
+
+ /* NFSv4 compound */
+ u32 rq_opcnt;
+ u32 rq_opnum[NFSD_MAX_OPS_PER_COMPOUND];
+};
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 433154b9eee0c..c5890cdfe97bd 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -997,6 +997,15 @@ 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:
@@ -1014,6 +1023,12 @@ 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 6bbb1d0276b4f..f96eaa8e9413d 100644
--- a/fs/nfsd/state.h
+++ b/fs/nfsd/state.h
@@ -195,8 +195,6 @@ 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 c1feaf0d15429..b10f987509cc8 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 */
--
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