From: neilbrown <neilbrown>
Date: Wed, 21 May 2003 06:44:50 +0000 (+0000)
Subject: enhance exportfs to use new cache/upcall stuff
X-Git-Tag: nfs-utils-1-1-0-pre3^0
X-Git-Url: https://git.decadent.org.uk/gitweb/?a=commitdiff_plain;h=2d33968c66860ad772aac918992986fe4865b3a4;p=nfs-utils.git

enhance exportfs to use new cache/upcall stuff
---

diff --git a/ChangeLog b/ChangeLog
index 654469b..b7da691 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2003-05-21  NeilBrown <neilb@cse.unsw.edu.au>
+
+	* utils/exportfs/exportfs.c: Use check_new_cache and cache_flush
+	 Don't actually talk to kernel when new cache is in effect, except
+	 to flush
+	* utils/exportfs/exportfs.c: add -f option to fully flush cache.
+	* support/export/xtab.c: Only rename new xtab into place if it has
+	 changed, thus preserving modify date for exportfs to use when
+	 flushing.
+	* support/nfs/cacheio.c: Add cache_flush
+	* support/export/xtab.c: Only rename new xtab into place if it has
+	 changed, thus preserving modify date for exportfs to use when
+	 flushing.
+	
 2003-05-21  NeilBrown <neilb@cse.unsw.edu.au>
 
 	* support/export/client.c: Add client_compose, client_member to
diff --git a/support/export/xtab.c b/support/export/xtab.c
index 3ef3661..d9265a2 100644
--- a/support/export/xtab.c
+++ b/support/export/xtab.c
@@ -18,6 +18,8 @@
 #include "xio.h"
 #include "xlog.h"
 
+static void cond_rename(char *newfile, char *oldfile);
+
 static int
 xtab_read(char *xtab, int is_export)
 {
@@ -104,7 +106,7 @@ xtab_write(char *xtab, char *xtabtmp, int is_export)
 	}
 	endexportent();
 
-	rename(xtabtmp, xtab);
+	cond_rename(xtabtmp, xtab);
 
 	xfunlock(lockid);
 
@@ -142,3 +144,46 @@ xtab_append(nfs_export *exp)
 	exp->m_xtabent = 1;
 }
 
+/*
+ * rename newfile onto oldfile unless
+ * they are identical 
+ */
+static void cond_rename(char *newfile, char *oldfile)
+{
+	int nfd, ofd;
+	char nbuf[4096], obuf[4096];
+	int ncnt, ocnt;
+
+	nfd = open(newfile, 0);
+	if (nfd < 0)
+		return;
+	ofd = open(oldfile, 0);
+	if (ofd < 0) {
+		close(nfd);
+		rename(newfile, oldfile);
+		return;
+	}
+
+	do {
+		ncnt = read(nfd, nbuf, sizeof(nbuf));
+		if (ncnt < 0)
+			break;
+		ocnt = read(ofd, obuf, sizeof(obuf));
+		if (ocnt < 0)
+			break;
+		if (ncnt != ocnt)
+			break;
+		if (ncnt == 0) {
+			close(nfd);
+			close(ofd);
+			unlink(newfile);
+			return;
+		}
+	} while (memcmp(obuf, nbuf, ncnt) == 0);
+
+	/* some mis-match */
+	close(nfd);
+	close(ofd);
+	rename(newfile, oldfile);
+	return;
+}
diff --git a/support/include/nfslib.h b/support/include/nfslib.h
index 5112b91..5864305 100644
--- a/support/include/nfslib.h
+++ b/support/include/nfslib.h
@@ -129,6 +129,7 @@ void qword_eol(FILE *f);
 int readline(int fd, char **buf, int *lenp);
 int qword_get(char **bpp, char *dest, int bufsize);
 int qword_get_int(char **bpp, int *anint);
+void cache_flush(int force);
 int check_new_cache(void);
 
 /* lockd. */
diff --git a/support/nfs/cacheio.c b/support/nfs/cacheio.c
index 2af4fa3..77facb1 100644
--- a/support/nfs/cacheio.c
+++ b/support/nfs/cacheio.c
@@ -230,3 +230,39 @@ check_new_cache(void)
 	return (stat("/proc/fs/nfs/filehandle", &stb) == 0);
 }	
 
+
+/* flush the kNFSd caches.
+ * Set the flush time to the mtime of _PATH_ETAB or
+ * if force, to now.
+ * the caches to flush are:
+ *  auth.unix.ip nfsd.export nfsd.fh
+ */
+
+void
+cache_flush(int force)
+{
+	struct stat stb;
+	int c;
+	char stime[20];
+	char path[200];
+	static char *cachelist[] = {
+		"auth.unix.ip",
+		"nfsd.export",
+		"nfsd.fh",
+		NULL
+	};
+	stb.st_mtime = time(0);
+	if (!force)
+		stat(_PATH_ETAB, &stb);
+	
+	sprintf(stime, "%ld\n", stb.st_mtime);
+	for (c=0; cachelist[c]; c++) {
+		int fd;
+		sprintf(path, "/proc/net/rpc/%s/flush", cachelist[c]);
+		fd = open(path, O_RDWR);
+		if (fd) {
+			write(fd, stime, strlen(stime));
+			close(fd);
+		}
+	}
+}
diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
index 05ace88..936dff5 100644
--- a/utils/exportfs/exportfs.c
+++ b/utils/exportfs/exportfs.c
@@ -42,12 +42,14 @@ main(int argc, char **argv)
 	int	f_reexport = 0;
 	int	f_ignore = 0;
 	int	i, c;
+	int	new_cache = 0;
+	int	force_flush = 0;
 
 	xlog_open("exportfs");
 
 	export_errno = 0;
 
-	while ((c = getopt(argc, argv, "aio:ruv")) != EOF) {
+	while ((c = getopt(argc, argv, "aio:ruvf")) != EOF) {
 		switch(c) {
 		case 'a':
 			f_all = 1;
@@ -68,6 +70,9 @@ main(int argc, char **argv)
 		case 'v':
 			f_verbose = 1;
 			break;
+		case 'f':
+			force_flush = 1;
+			break;
 		default:
 			usage();
 			break;
@@ -92,6 +97,8 @@ main(int argc, char **argv)
 		return 0;
 	}
 
+	new_cache = check_new_cache();
+
 	if (f_export && ! f_ignore)
 		export_read(_PATH_EXPORTS);
 	if (f_export) {
@@ -116,10 +123,15 @@ main(int argc, char **argv)
 				unexportfs(argv[i], f_verbose);
 		rmtab_read();
 	}
-	xtab_mount_read();
-	exports_update(f_verbose);
+	if (!new_cache) {
+		xtab_mount_read();
+		exports_update(f_verbose);
+	}
 	xtab_export_write();
-	xtab_mount_write();
+	if (new_cache)
+		cache_flush(force_flush);
+	if (!new_cache)
+		xtab_mount_write();
 
 	return export_errno;
 }
@@ -267,19 +279,22 @@ unexportfs(char *arg, int verbose)
 					  hname)))
 			continue;
 		if (verbose) {
+#if 0
 			if (exp->m_exported) {
 				printf("unexporting %s:%s from kernel\n",
 				       exp->m_client->m_hostname,
 				       exp->m_export.e_path);
 			}
-			else {
+			else
+#endif
 				printf("unexporting %s:%s\n",
 					exp->m_client->m_hostname, 
 					exp->m_export.e_path);
-			}
 		}
+#if 0
 		if (exp->m_exported && !export_unexport(exp))
 			error(exp, errno);
+#endif
 		exp->m_xtabent = 0;
 		exp->m_mayexport = 0;
 	}