enhance exportfs to use new cache/upcall stuff

3 files changed, 83 insertions, 1 deletions

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);
+		}
+	}
+}