svn commit: r197840 - head/sys/nlm
Zachary Loafman
zml at FreeBSD.org
Wed Oct 7 19:50:14 UTC 2009
Author: zml
Date: Wed Oct 7 19:50:14 2009
New Revision: 197840
URL: http://svn.freebsd.org/changeset/base/197840
Log:
Handle GRANTED_RES messages more gracefully: Send along a grant cookie
to reference the lock, look up the grant cookie when the GRANTED_RES
comes back. Properly handle the case of an error on the grant. Add a
short expiration window so that granted locks are not freed immediately.
Approved by: dfr (mentor)
MFC after: 2 weeks
Modified:
head/sys/nlm/nlm.h
head/sys/nlm/nlm_prot_impl.c
head/sys/nlm/nlm_prot_server.c
Modified: head/sys/nlm/nlm.h
==============================================================================
--- head/sys/nlm/nlm.h Wed Oct 7 15:41:30 2009 (r197839)
+++ head/sys/nlm/nlm.h Wed Oct 7 19:50:14 2009 (r197840)
@@ -49,6 +49,12 @@ extern struct timeval nlm_zero_tv;
extern int nlm_nsm_state;
/*
+ * Make a struct netobj.
+ */
+extern void nlm_make_netobj(struct netobj *dst, caddr_t srt,
+ size_t srcsize, struct malloc_type *type);
+
+/*
* Copy a struct netobj.
*/
extern void nlm_copy_netobj(struct netobj *dst, struct netobj *src,
@@ -193,6 +199,12 @@ extern int nlm_do_granted(nlm4_testargs
struct svc_req *rqstp, CLIENT **rpcp);
/*
+ * Implementation for the granted result RPC. The client may reject the granted
+ * message, in which case we need to handle it appropriately.
+ */
+extern void nlm_do_granted_res(nlm4_res *argp, struct svc_req *rqstp);
+
+/*
* Free all locks associated with the hostname argp->name.
*/
extern void nlm_do_free_all(nlm4_notify *argp);
Modified: head/sys/nlm/nlm_prot_impl.c
==============================================================================
--- head/sys/nlm/nlm_prot_impl.c Wed Oct 7 15:41:30 2009 (r197839)
+++ head/sys/nlm/nlm_prot_impl.c Wed Oct 7 19:50:14 2009 (r197840)
@@ -31,6 +31,7 @@
__FBSDID("$FreeBSD$");
#include <sys/param.h>
+#include <sys/fail.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
@@ -77,6 +78,11 @@ MALLOC_DEFINE(M_NLM, "NLM", "Network Loc
#define NLM_IDLE_PERIOD 5
/*
+ * We only look for GRANTED_RES messages for a little while.
+ */
+#define NLM_EXPIRE_TIMEOUT 10
+
+/*
* Support for sysctl vfs.nlm.sysid
*/
SYSCTL_NODE(_vfs, OID_AUTO, nlm, CTLFLAG_RW, NULL, "Network Lock Manager");
@@ -204,6 +210,7 @@ struct nlm_async_lock {
struct nlm_host *af_host; /* (c) host which is locking */
CLIENT *af_rpc; /* (c) rpc client to send message */
nlm4_testargs af_granted; /* (c) notification details */
+ time_t af_expiretime; /* (c) notification time */
};
TAILQ_HEAD(nlm_async_lock_list, nlm_async_lock);
@@ -237,7 +244,9 @@ struct nlm_host {
enum nlm_host_state nh_monstate; /* (l) local NSM monitoring state */
time_t nh_idle_timeout; /* (s) Time at which host is idle */
struct sysctl_ctx_list nh_sysctl; /* (c) vfs.nlm.sysid nodes */
+ uint32_t nh_grantcookie; /* (l) grant cookie counter */
struct nlm_async_lock_list nh_pending; /* (l) pending async locks */
+ struct nlm_async_lock_list nh_granted; /* (l) granted locks */
struct nlm_async_lock_list nh_finished; /* (l) finished async locks */
};
TAILQ_HEAD(nlm_host_list, nlm_host);
@@ -247,6 +256,25 @@ static uint32_t nlm_next_sysid = 1; /
static void nlm_host_unmonitor(struct nlm_host *);
+struct nlm_grantcookie {
+ uint32_t ng_sysid;
+ uint32_t ng_cookie;
+};
+
+static inline uint32_t
+ng_sysid(struct netobj *src)
+{
+
+ return ((struct nlm_grantcookie *)src->n_bytes)->ng_sysid;
+}
+
+static inline uint32_t
+ng_cookie(struct netobj *src)
+{
+
+ return ((struct nlm_grantcookie *)src->n_bytes)->ng_cookie;
+}
+
/**********************************************************************/
/*
@@ -281,6 +309,19 @@ nlm_uninit(void *dummy)
SYSUNINIT(nlm_uninit, SI_SUB_LOCK, SI_ORDER_FIRST, nlm_uninit, NULL);
/*
+ * Create a netobj from an arbitrary source.
+ */
+void
+nlm_make_netobj(struct netobj *dst, caddr_t src, size_t srcsize,
+ struct malloc_type *type)
+{
+
+ dst->n_len = srcsize;
+ dst->n_bytes = malloc(srcsize, type, M_WAITOK);
+ memcpy(dst->n_bytes, src, srcsize);
+}
+
+/*
* Copy a struct netobj.
*/
void
@@ -288,11 +329,10 @@ nlm_copy_netobj(struct netobj *dst, stru
struct malloc_type *type)
{
- dst->n_len = src->n_len;
- dst->n_bytes = malloc(src->n_len, type, M_WAITOK);
- memcpy(dst->n_bytes, src->n_bytes, src->n_len);
+ nlm_make_netobj(dst, src->n_bytes, src->n_len, type);
}
+
/*
* Create an RPC client handle for the given (address,prog,vers)
* triple using UDP.
@@ -518,8 +558,10 @@ nlm_lock_callback(void *arg, int pending
struct nlm_async_lock *af = (struct nlm_async_lock *) arg;
struct rpc_callextra ext;
- NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) granted\n",
- af, af->af_host->nh_caller_name, af->af_host->nh_sysid);
+ NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) granted,"
+ " cookie %d:%d\n", af, af->af_host->nh_caller_name,
+ af->af_host->nh_sysid, ng_sysid(&af->af_granted.cookie),
+ ng_cookie(&af->af_granted.cookie));
/*
* Send the results back to the host.
@@ -556,16 +598,12 @@ nlm_lock_callback(void *arg, int pending
}
/*
- * Move this entry to the nh_finished list. Someone else will
- * free it later - its too hard to do it here safely without
- * racing with cancel.
- *
- * XXX possibly we should have a third "granted sent but not
- * ack'ed" list so that we can re-send the granted message.
+ * Move this entry to the nh_granted list.
*/
+ af->af_expiretime = time_uptime + NLM_EXPIRE_TIMEOUT;
mtx_lock(&af->af_host->nh_lock);
TAILQ_REMOVE(&af->af_host->nh_pending, af, af_link);
- TAILQ_INSERT_TAIL(&af->af_host->nh_finished, af, af_link);
+ TAILQ_INSERT_TAIL(&af->af_host->nh_granted, af, af_link);
mtx_unlock(&af->af_host->nh_lock);
}
@@ -635,11 +673,23 @@ nlm_cancel_async_lock(struct nlm_async_l
}
static void
-nlm_free_finished_locks(struct nlm_host *host)
+nlm_check_expired_locks(struct nlm_host *host)
{
struct nlm_async_lock *af;
+ time_t uptime = time_uptime;
mtx_lock(&host->nh_lock);
+ while ((af = TAILQ_FIRST(&host->nh_granted)) != NULL
+ && uptime >= af->af_expiretime) {
+ NLM_DEBUG(2, "NLM: async lock %p for %s (sysid %d) expired,"
+ " cookie %d:%d\n", af, af->af_host->nh_caller_name,
+ af->af_host->nh_sysid, ng_sysid(&af->af_granted.cookie),
+ ng_cookie(&af->af_granted.cookie));
+ TAILQ_REMOVE(&host->nh_granted, af, af_link);
+ mtx_unlock(&host->nh_lock);
+ nlm_free_async_lock(af);
+ mtx_lock(&host->nh_lock);
+ }
while ((af = TAILQ_FIRST(&host->nh_finished)) != NULL) {
TAILQ_REMOVE(&host->nh_finished, af, af_link);
mtx_unlock(&host->nh_lock);
@@ -722,7 +772,7 @@ nlm_host_notify(struct nlm_host *host, i
nlm_cancel_async_lock(af);
}
mtx_unlock(&host->nh_lock);
- nlm_free_finished_locks(host);
+ nlm_check_expired_locks(host);
/*
* The host just rebooted - trash its locks.
@@ -799,7 +849,9 @@ nlm_create_host(const char* caller_name)
host->nh_vers = 0;
host->nh_state = 0;
host->nh_monstate = NLM_UNMONITORED;
+ host->nh_grantcookie = 1;
TAILQ_INIT(&host->nh_pending);
+ TAILQ_INIT(&host->nh_granted);
TAILQ_INIT(&host->nh_finished);
TAILQ_INSERT_TAIL(&nlm_hosts, host, nh_link);
@@ -1834,7 +1886,7 @@ nlm_do_test(nlm4_testargs *argp, nlm4_te
NLM_DEBUG(3, "nlm_do_test(): caller_name = %s (sysid = %d)\n",
host->nh_caller_name, host->nh_sysid);
- nlm_free_finished_locks(host);
+ nlm_check_expired_locks(host);
sysid = host->nh_sysid;
nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
@@ -1939,7 +1991,7 @@ nlm_do_lock(nlm4_lockargs *argp, nlm4_re
nlm_host_notify(host, argp->state);
}
- nlm_free_finished_locks(host);
+ nlm_check_expired_locks(host);
sysid = host->nh_sysid;
nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
@@ -1968,6 +2020,7 @@ nlm_do_lock(nlm4_lockargs *argp, nlm4_re
if (argp->block) {
struct nlm_async_lock *af;
CLIENT *client;
+ struct nlm_grantcookie cookie;
/*
* First, make sure we can contact the host's NLM.
@@ -1993,6 +2046,10 @@ nlm_do_lock(nlm4_lockargs *argp, nlm4_re
break;
}
}
+ if (!af) {
+ cookie.ng_sysid = host->nh_sysid;
+ cookie.ng_cookie = host->nh_grantcookie++;
+ }
mtx_unlock(&host->nh_lock);
if (af) {
CLNT_RELEASE(client);
@@ -2011,6 +2068,8 @@ nlm_do_lock(nlm4_lockargs *argp, nlm4_re
* We use M_RPC here so that we can xdr_free the thing
* later.
*/
+ nlm_make_netobj(&af->af_granted.cookie,
+ (caddr_t)&cookie, sizeof(cookie), M_RPC);
af->af_granted.exclusive = argp->exclusive;
af->af_granted.alock.caller_name =
strdup(argp->alock.caller_name, M_RPC);
@@ -2111,7 +2170,7 @@ nlm_do_cancel(nlm4_cancargs *argp, nlm4_
NLM_DEBUG(3, "nlm_do_cancel(): caller_name = %s (sysid = %d)\n",
host->nh_caller_name, host->nh_sysid);
- nlm_free_finished_locks(host);
+ nlm_check_expired_locks(host);
sysid = host->nh_sysid;
nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
@@ -2200,7 +2259,7 @@ nlm_do_unlock(nlm4_unlockargs *argp, nlm
NLM_DEBUG(3, "nlm_do_unlock(): caller_name = %s (sysid = %d)\n",
host->nh_caller_name, host->nh_sysid);
- nlm_free_finished_locks(host);
+ nlm_check_expired_locks(host);
sysid = host->nh_sysid;
nlm_convert_to_fhandle_t(&fh, &argp->alock.fh);
@@ -2257,6 +2316,7 @@ nlm_do_granted(nlm4_testargs *argp, nlm4
nlm_copy_netobj(&result->cookie, &argp->cookie, M_RPC);
result->stat.stat = nlm4_denied;
+ KFAIL_POINT_CODE(DEBUG_FP, nlm_deny_grant, goto out);
mtx_lock(&nlm_global_lock);
TAILQ_FOREACH(nw, &nlm_waiting_locks, nw_link) {
@@ -2275,6 +2335,8 @@ nlm_do_granted(nlm4_testargs *argp, nlm4
}
}
mtx_unlock(&nlm_global_lock);
+
+out:
if (rpcp)
*rpcp = nlm_host_get_rpc(host, TRUE);
nlm_host_release(host);
@@ -2282,6 +2344,65 @@ nlm_do_granted(nlm4_testargs *argp, nlm4
}
void
+nlm_do_granted_res(nlm4_res *argp, struct svc_req *rqstp)
+{
+ struct nlm_host *host = NULL;
+ struct nlm_async_lock *af = NULL;
+ int error;
+
+ if (argp->cookie.n_len != sizeof(struct nlm_grantcookie)) {
+ NLM_DEBUG(1, "NLM: bogus grant cookie");
+ goto out;
+ }
+
+ host = nlm_find_host_by_sysid(ng_sysid(&argp->cookie));
+ if (!host) {
+ NLM_DEBUG(1, "NLM: Unknown host rejected our grant");
+ goto out;
+ }
+
+ mtx_lock(&host->nh_lock);
+ TAILQ_FOREACH(af, &host->nh_granted, af_link)
+ if (ng_cookie(&argp->cookie) ==
+ ng_cookie(&af->af_granted.cookie))
+ break;
+ if (af)
+ TAILQ_REMOVE(&host->nh_granted, af, af_link);
+ mtx_unlock(&host->nh_lock);
+
+ if (!af) {
+ NLM_DEBUG(1, "NLM: host %s (sysid %d) replied to our grant "
+ "with unrecognized cookie %d:%d", host->nh_caller_name,
+ host->nh_sysid, ng_sysid(&argp->cookie),
+ ng_cookie(&argp->cookie));
+ goto out;
+ }
+
+ if (argp->stat.stat != nlm4_granted) {
+ af->af_fl.l_type = F_UNLCK;
+ error = VOP_ADVLOCK(af->af_vp, NULL, F_UNLCK, &af->af_fl, F_REMOTE);
+ if (error) {
+ NLM_DEBUG(1, "NLM: host %s (sysid %d) rejected our grant "
+ "and we failed to unlock (%d)", host->nh_caller_name,
+ host->nh_sysid, error);
+ goto out;
+ }
+
+ NLM_DEBUG(5, "NLM: async lock %p rejected by host %s (sysid %d)",
+ af, host->nh_caller_name, host->nh_sysid);
+ } else {
+ NLM_DEBUG(5, "NLM: async lock %p accepted by host %s (sysid %d)",
+ af, host->nh_caller_name, host->nh_sysid);
+ }
+
+ out:
+ if (af)
+ nlm_free_async_lock(af);
+ if (host)
+ nlm_host_release(host);
+}
+
+void
nlm_do_free_all(nlm4_notify *argp)
{
struct nlm_host *host, *thost;
Modified: head/sys/nlm/nlm_prot_server.c
==============================================================================
--- head/sys/nlm/nlm_prot_server.c Wed Oct 7 15:41:30 2009 (r197839)
+++ head/sys/nlm/nlm_prot_server.c Wed Oct 7 19:50:14 2009 (r197840)
@@ -671,6 +671,7 @@ bool_t
nlm4_granted_res_4_svc(nlm4_res *argp, void *result, struct svc_req *rqstp)
{
+ nlm_do_granted_res(argp, rqstp);
return (FALSE);
}
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