lockd: Relocate svc_version definitions to XDR layer

Public RPC server interfaces become cluttered when internal
XDR implementation details leak into them. The procedure count,
maximum XDR buffer size, and per-CPU call counters serve no
purpose outside the code that encodes and decodes NLM protocol
messages. Exposing these values through global headers creates
unnecessary coupling between the RPC dispatch logic and the
XDR layer.

Relocating the svc_version structure definitions confines this
implementation information to the files where XDR encoding and
decoding occur. In svc.c, the buffer size computation now reads
vs_xdrsize from the version structures rather than relying on a
preprocessor constant. This calculation occurs at service
initialization, after the linker has resolved the version
structure definitions. The dispatch function becomes non-static
because both the version structures and the dispatcher reside in
different translation units.

The NLMSVC_XDRSIZE macro is removed from xdr.h because buffer
size is now computed from the union of XDR argument and result
structures, matching the pattern used in other RPC services.
Version 1 and 3 share the same procedure table but maintain
separate counter arrays. Version 4 remains separate due to its
distinct procedure definitions.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/fs/lockd/lockd.h b/fs/lockd/lockd.h
index ef6431b4cac0663c33860298825b1d1564f27d1d..ad4c6701b64a7ddd9b1c47e6bd88c447f04176ab 100644 (file)
--- a/fs/lockd/lockd.h
+++ b/fs/lockd/lockd.h
@@ -221,9 +221,10 @@ struct nlm_block {
  * Global variables
  */
 extern const struct rpc_program        nlm_program;
-extern const struct svc_procedure nlmsvc_procedures[24];
+extern const struct svc_version nlmsvc_version1;
+extern const struct svc_version nlmsvc_version3;
 #ifdef CONFIG_LOCKD_V4
-extern const struct svc_procedure nlmsvc_procedures4[24];
+extern const struct svc_version nlmsvc_version4;
 #endif
 extern int                     nlmsvc_grace_period;
 extern unsigned long           nlm_timeout;
@@ -318,6 +319,7 @@ void                  nlmsvc_traverse_blocks(struct nlm_host *, struct nlm_file *,
 void             nlmsvc_grant_reply(struct nlm_cookie *, __be32);
 void             nlmsvc_release_call(struct nlm_rqst *);
 void             nlmsvc_locks_init_private(struct file_lock *, struct nlm_host *, pid_t);
+int              nlmsvc_dispatch(struct svc_rqst *rqstp);
 
 /*
  * File handling for the server personality

diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 9dd7f8e1154412d21c3c66ecc15503f819dfad56..490551369ef2a97cfb90d06b520f2425b9aaca38 100644 (file)
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -44,7 +44,6 @@
 #include "netlink.h"
 
 #define NLMDBG_FACILITY                NLMDBG_SVC
-#define LOCKD_BUFSIZE          (1024 + NLMSVC_XDRSIZE)
 
 static struct svc_program      nlmsvc_program;
 
@@ -319,6 +318,7 @@ static struct notifier_block lockd_inet6addr_notifier = {
 static int lockd_get(void)
 {
        struct svc_serv *serv;
+       unsigned int bufsize;
        int error;
 
        if (nlmsvc_serv) {
@@ -334,7 +334,15 @@ static int lockd_get(void)
                printk(KERN_WARNING
                        "lockd_up: no pid, %d users??\n", nlmsvc_users);
 
-       serv = svc_create(&nlmsvc_program, LOCKD_BUFSIZE, lockd);
+#ifdef CONFIG_LOCKD_V4
+       bufsize = 1024 + max3(nlmsvc_version1.vs_xdrsize,
+                             nlmsvc_version3.vs_xdrsize,
+                             nlmsvc_version4.vs_xdrsize);
+#else
+       bufsize = 1024 + max(nlmsvc_version1.vs_xdrsize,
+                            nlmsvc_version3.vs_xdrsize);
+#endif
+       serv = svc_create(&nlmsvc_program, bufsize, lockd);
        if (!serv) {
                printk(KERN_WARNING "lockd_up: create service failed\n");
                return -ENOMEM;
@@ -640,7 +648,7 @@ module_exit(exit_nlm);
  *  %0: Processing complete; do not send a Reply
  *  %1: Processing complete; send Reply in rqstp->rq_res
  */
-static int nlmsvc_dispatch(struct svc_rqst *rqstp)
+int nlmsvc_dispatch(struct svc_rqst *rqstp)
 {
        const struct svc_procedure *procp = rqstp->rq_procinfo;
        __be32 *statp = rqstp->rq_accept_statp;
@@ -671,40 +679,6 @@ out_encode_err:
 /*
  * Define NLM program and procedures
  */
-static DEFINE_PER_CPU_ALIGNED(unsigned long, nlmsvc_version1_count[17]);
-static const struct svc_version        nlmsvc_version1 = {
-       .vs_vers        = 1,
-       .vs_nproc       = 17,
-       .vs_proc        = nlmsvc_procedures,
-       .vs_count       = nlmsvc_version1_count,
-       .vs_dispatch    = nlmsvc_dispatch,
-       .vs_xdrsize     = NLMSVC_XDRSIZE,
-};
-
-static DEFINE_PER_CPU_ALIGNED(unsigned long,
-                             nlmsvc_version3_count[ARRAY_SIZE(nlmsvc_procedures)]);
-static const struct svc_version        nlmsvc_version3 = {
-       .vs_vers        = 3,
-       .vs_nproc       = ARRAY_SIZE(nlmsvc_procedures),
-       .vs_proc        = nlmsvc_procedures,
-       .vs_count       = nlmsvc_version3_count,
-       .vs_dispatch    = nlmsvc_dispatch,
-       .vs_xdrsize     = NLMSVC_XDRSIZE,
-};
-
-#ifdef CONFIG_LOCKD_V4
-static DEFINE_PER_CPU_ALIGNED(unsigned long,
-                             nlmsvc_version4_count[ARRAY_SIZE(nlmsvc_procedures4)]);
-static const struct svc_version        nlmsvc_version4 = {
-       .vs_vers        = 4,
-       .vs_nproc       = ARRAY_SIZE(nlmsvc_procedures4),
-       .vs_proc        = nlmsvc_procedures4,
-       .vs_count       = nlmsvc_version4_count,
-       .vs_dispatch    = nlmsvc_dispatch,
-       .vs_xdrsize     = NLMSVC_XDRSIZE,
-};
-#endif
-
 static const struct svc_version *nlmsvc_version[] = {
        [1] = &nlmsvc_version1,
        [3] = &nlmsvc_version3,

diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
index 86dfeb6ce68d415528b462b0f117945a1a5f116b..c99f192bce77c3d6300fb99aa66fde114c568acd 100644 (file)
--- a/fs/lockd/svc4proc.c
+++ b/fs/lockd/svc4proc.c
@@ -530,7 +530,7 @@ struct nlm_void                     { int dummy; };
 #define        St      1                                       /* status */
 #define        Rg      4                                       /* range (offset + length) */
 
-const struct svc_procedure nlmsvc_procedures4[24] = {
+static const struct svc_procedure nlm4svc_procedures[24] = {
        [NLMPROC_NULL] = {
                .pc_func = nlm4svc_proc_null,
                .pc_decode = nlm4svc_decode_void,
@@ -772,3 +772,24 @@ const struct svc_procedure nlmsvc_procedures4[24] = {
                .pc_name = "FREE_ALL",
        },
 };
+
+/*
+ * Storage requirements for XDR arguments and results
+ */
+union nlm4svc_xdrstore {
+       struct nlm_args                 args;
+       struct nlm_res                  res;
+       struct nlm_reboot               reboot;
+};
+
+static DEFINE_PER_CPU_ALIGNED(unsigned long,
+                             nlm4svc_call_counters[ARRAY_SIZE(nlm4svc_procedures)]);
+
+const struct svc_version nlmsvc_version4 = {
+       .vs_vers        = 4,
+       .vs_nproc       = ARRAY_SIZE(nlm4svc_procedures),
+       .vs_proc        = nlm4svc_procedures,
+       .vs_count       = nlm4svc_call_counters,
+       .vs_dispatch    = nlmsvc_dispatch,
+       .vs_xdrsize     = sizeof(union nlm4svc_xdrstore),
+};

diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
index e9a6bcc3bf2e9348476b0e2674e6477039eeb3e9..75b0dfa1a79a7bd20981eda4a3c072dc5975a95f 100644 (file)
--- a/fs/lockd/svcproc.c
+++ b/fs/lockd/svcproc.c
@@ -555,7 +555,7 @@ struct nlm_void                     { int dummy; };
 #define        No      (1+1024/4)                      /* Net Obj */
 #define        Rg      2                               /* range - offset + size */
 
-const struct svc_procedure nlmsvc_procedures[24] = {
+static const struct svc_procedure nlmsvc_procedures[24] = {
        [NLMPROC_NULL] = {
                .pc_func = nlmsvc_proc_null,
                .pc_decode = nlmsvc_decode_void,
@@ -797,3 +797,39 @@ const struct svc_procedure nlmsvc_procedures[24] = {
                .pc_name = "FREE_ALL",
        },
 };
+
+/*
+ * Storage requirements for XDR arguments and results
+ */
+union nlmsvc_xdrstore {
+       struct nlm_args                 args;
+       struct nlm_res                  res;
+       struct nlm_reboot               reboot;
+};
+
+/*
+ * NLMv1 defines only procedures 1 - 15. Linux lockd also implements
+ * procedures 0 (NULL) and 16 (SM_NOTIFY).
+ */
+static DEFINE_PER_CPU_ALIGNED(unsigned long, nlm1svc_call_counters[17]);
+
+const struct svc_version nlmsvc_version1 = {
+       .vs_vers        = 1,
+       .vs_nproc       = 17,
+       .vs_proc        = nlmsvc_procedures,
+       .vs_count       = nlm1svc_call_counters,
+       .vs_dispatch    = nlmsvc_dispatch,
+       .vs_xdrsize     = sizeof(union nlmsvc_xdrstore),
+};
+
+static DEFINE_PER_CPU_ALIGNED(unsigned long,
+                             nlm3svc_call_counters[ARRAY_SIZE(nlmsvc_procedures)]);
+
+const struct svc_version nlmsvc_version3 = {
+       .vs_vers        = 3,
+       .vs_nproc       = ARRAY_SIZE(nlmsvc_procedures),
+       .vs_proc        = nlmsvc_procedures,
+       .vs_count       = nlm3svc_call_counters,
+       .vs_dispatch    = nlmsvc_dispatch,
+       .vs_xdrsize     = sizeof(union nlmsvc_xdrstore),
+};

diff --git a/fs/lockd/xdr.h b/fs/lockd/xdr.h
index af821ecf2a4e6d4eb65c5105044c08019bc31730..3c60817c4349a0d22a83808caf91b6cc2139bf7e 100644 (file)
--- a/fs/lockd/xdr.h
+++ b/fs/lockd/xdr.h
@@ -88,11 +88,6 @@ struct nlm_reboot {
        struct nsm_private      priv;
 };
 
-/*
- * Contents of statd callback when monitored host rebooted
- */
-#define NLMSVC_XDRSIZE         sizeof(struct nlm_args)
-
 bool   nlmsvc_decode_void(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool   nlmsvc_decode_testargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);
 bool   nlmsvc_decode_lockargs(struct svc_rqst *rqstp, struct xdr_stream *xdr);