diff mbox series

[v1] Revert "SUNRPC: Use RMW bitops in single-threaded hot paths"

Message ID 167302701777.4221.807573588471189662.stgit@klimt.1015granger.net (mailing list archive)
State New, archived
Headers show
Series [v1] Revert "SUNRPC: Use RMW bitops in single-threaded hot paths" | expand

Commit Message

Chuck Lever Jan. 6, 2023, 5:43 p.m. UTC 
From: Chuck Lever <chuck.lever@oracle.com>

The premise that "Once an svc thread is scheduled and executing an
RPC, no other processes will touch svc_rqst::rq_flags" is false.
svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
threads when determining which thread to wake up next.

Found via KCSAN.

Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfsd/nfs4proc.c                       |    7 +++----
 fs/nfsd/nfs4xdr.c                        |    2 +-
 net/sunrpc/auth_gss/svcauth_gss.c        |    4 ++--
 net/sunrpc/svc.c                         |    6 +++---
 net/sunrpc/svc_xprt.c                    |    2 +-
 net/sunrpc/svcsock.c                     |    8 ++++----
 net/sunrpc/xprtrdma/svc_rdma_transport.c |    2 +-
 7 files changed, 15 insertions(+), 16 deletions(-)

Comments

Jeff Layton Jan. 6, 2023, 5:57 p.m. UTC | #1 
On Fri, 2023-01-06 at 12:43 -0500, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> The premise that "Once an svc thread is scheduled and executing an
> RPC, no other processes will touch svc_rqst::rq_flags" is false.
> svc_xprt_enqueue() examines the RQ_BUSY flag in scheduled nfsd
> threads when determining which thread to wake up next.
> 
> Found via KCSAN.
> 
> Fixes: 28df0988815f ("SUNRPC: Use RMW bitops in single-threaded hot paths")
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfs4proc.c                       |    7 +++----
>  fs/nfsd/nfs4xdr.c                        |    2 +-
>  net/sunrpc/auth_gss/svcauth_gss.c        |    4 ++--
>  net/sunrpc/svc.c                         |    6 +++---
>  net/sunrpc/svc_xprt.c                    |    2 +-
>  net/sunrpc/svcsock.c                     |    8 ++++----
>  net/sunrpc/xprtrdma/svc_rdma_transport.c |    2 +-
>  7 files changed, 15 insertions(+), 16 deletions(-)
> 

Makes sense.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff mbox series

Patch

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index bd880d55f565..9b81d012666e 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -937,7 +937,7 @@  nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 	 * the client wants us to do more in this compound:
 	 */
 	if (!nfsd4_last_compound_op(rqstp))
-		__clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+		clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
 	/* check stateid */
 	status = nfs4_preprocess_stateid_op(rqstp, cstate, &cstate->current_fh,
@@ -2607,12 +2607,11 @@  nfsd4_proc_compound(struct svc_rqst *rqstp)
 	cstate->minorversion = args->minorversion;
 	fh_init(current_fh, NFS4_FHSIZE);
 	fh_init(save_fh, NFS4_FHSIZE);
-
 	/*
 	 * Don't use the deferral mechanism for NFSv4; compounds make it
 	 * too hard to avoid non-idempotency problems.
 	 */
-	__clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+	clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
 
 	/*
 	 * According to RFC3010, this takes precedence over all other errors.
@@ -2734,7 +2733,7 @@  nfsd4_proc_compound(struct svc_rqst *rqstp)
 out:
 	cstate->status = status;
 	/* Reset deferral mechanism for RPC deferrals */
-	__set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+	set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
 	return rpc_success;
 }
 
diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index ebb4d02a42ce..97edb32be77f 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -2523,7 +2523,7 @@  nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
 
 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
-		__clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
+		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
 
 	return true;
 }
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index 148bb0a7fa5b..acb822b23af1 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -923,7 +923,7 @@  unwrap_integ_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct g
 	 * rejecting the server-computed MIC in this somewhat rare case,
 	 * do not use splice with the GSS integrity service.
 	 */
-	__clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+	clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
 	/* Did we already verify the signature on the original pass through? */
 	if (rqstp->rq_deferred)
@@ -990,7 +990,7 @@  unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct gs
 	int pad, remaining_len, offset;
 	u32 rseqno;
 
-	__clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+	clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
 	priv_len = svc_getnl(&buf->head[0]);
 	if (rqstp->rq_deferred) {
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 8f1b596db33f..b1da586c4476 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1243,10 +1243,10 @@  svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 		goto err_short_len;
 
 	/* Will be turned off by GSS integrity and privacy services */
-	__set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
+	set_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 	/* Will be turned off only when NFSv4 Sessions are used */
-	__set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
-	__clear_bit(RQ_DROPME, &rqstp->rq_flags);
+	set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
+	clear_bit(RQ_DROPME, &rqstp->rq_flags);
 
 	svc_putu32(resv, rqstp->rq_xid);
 
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 2106003645a7..c2ce12538008 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -1238,7 +1238,7 @@  static struct cache_deferred_req *svc_defer(struct cache_req *req)
 	trace_svc_defer(rqstp);
 	svc_xprt_get(rqstp->rq_xprt);
 	dr->xprt = rqstp->rq_xprt;
-	__set_bit(RQ_DROPME, &rqstp->rq_flags);
+	set_bit(RQ_DROPME, &rqstp->rq_flags);
 
 	dr->handle.revisit = svc_revisit;
 	return &dr->handle;
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 2fc98fea59b4..e833103f4629 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -298,9 +298,9 @@  static void svc_sock_setbufsize(struct svc_sock *svsk, unsigned int nreqs)
 static void svc_sock_secure_port(struct svc_rqst *rqstp)
 {
 	if (svc_port_is_privileged(svc_addr(rqstp)))
-		__set_bit(RQ_SECURE, &rqstp->rq_flags);
+		set_bit(RQ_SECURE, &rqstp->rq_flags);
 	else
-		__clear_bit(RQ_SECURE, &rqstp->rq_flags);
+		clear_bit(RQ_SECURE, &rqstp->rq_flags);
 }
 
 /*
@@ -1008,9 +1008,9 @@  static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 	rqstp->rq_xprt_ctxt   = NULL;
 	rqstp->rq_prot	      = IPPROTO_TCP;
 	if (test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags))
-		__set_bit(RQ_LOCAL, &rqstp->rq_flags);
+		set_bit(RQ_LOCAL, &rqstp->rq_flags);
 	else
-		__clear_bit(RQ_LOCAL, &rqstp->rq_flags);
+		clear_bit(RQ_LOCAL, &rqstp->rq_flags);
 
 	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
 	calldir = p[1];
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 199fa012f18a..94b20fb47135 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -602,7 +602,7 @@  static int svc_rdma_has_wspace(struct svc_xprt *xprt)
 
 static void svc_rdma_secure_port(struct svc_rqst *rqstp)
 {
-	__set_bit(RQ_SECURE, &rqstp->rq_flags);
+	set_bit(RQ_SECURE, &rqstp->rq_flags);
 }
 
 static void svc_rdma_kill_temp_xprt(struct svc_xprt *xprt)