new "mountpoint" export option.

6 files changed, 57 insertions, 1 deletions

diff --git a/support/export/export.c b/support/export/export.c
index ba0d095..eef2c3b 100644
--- a/support/export/export.c
+++ b/support/export/export.c
@@ -239,6 +239,8 @@ export_freeall(void)
 				xfree(exp->m_export.e_squids);
 			if (exp->m_export.e_sqgids)
 				xfree(exp->m_export.e_sqgids);
+			if (exp->m_export.e_mountpoint)
+				free(exp->m_export.e_mountpoint);
 			xfree(exp);
 		}
 		exportlist[i] = NULL;
diff --git a/support/include/misc.h b/support/include/misc.h
index 7d099d0..9a1b25d 100644
--- a/support/include/misc.h
+++ b/support/include/misc.h
@@ -22,4 +22,6 @@ struct hostent	*hostent_dup(struct hostent *hp);
 struct hostent	*get_hostent (const char *addr, int len, int type);
 struct hostent *get_reliable_hostbyaddr(const char *addr, int len, int type);
 
+extern int is_mountpoint(char *path);
+
 #endif /* MISC_H */
diff --git a/support/include/nfslib.h b/support/include/nfslib.h
index 5864305..c41f92e 100644
--- a/support/include/nfslib.h
+++ b/support/include/nfslib.h
@@ -73,6 +73,7 @@ struct exportent {
 	int *		e_sqgids;
 	int		e_nsqgids;
 	int		e_fsid;
+	char *		e_mountpoint;
 };
 
 struct rmtabent {
diff --git a/support/misc/Makefile b/support/misc/Makefile
index b2f73f8..c738564 100644
--- a/support/misc/Makefile
+++ b/support/misc/Makefile
@@ -3,7 +3,7 @@
 #
 
 LIBNAME	= libmisc.a
-OBJS	= tcpwrapper.o from_local.o
+OBJS	= tcpwrapper.o from_local.o mountpoint.o
 
 include $(TOP)rules.mk
 
diff --git a/support/misc/mountpoint.c b/support/misc/mountpoint.c
new file mode 100644
index 0000000..6d0f34e
--- /dev/null
+++ b/support/misc/mountpoint.c
@@ -0,0 +1,34 @@
+
+/*
+ * check if a given path is a mountpoint 
+ */
+
+#include <string.h>
+#include <malloc.h>
+#include <sys/stat.h>
+
+int
+is_mountpoint(char *path)
+{
+	/* Check if 'path' is a current mountpoint.
+	 * Possibly we should also check it is the mountpoint of the 
+	 * filesystem holding the target directory, but there doesn't
+	 * seem a lot of point.
+	 *
+	 * We deem it to be a mountpoint if appending a ".." gives a different
+	 * device or the same inode number.
+	 */
+	char *dotdot;
+	struct stat stb, pstb;
+
+	dotdot = malloc(strlen(path)+4);
+	strcat(strcpy(dotdot, path), "/..");
+	if (lstat(path, &stb) != 0 ||
+	    lstat(dotdot, &pstb) != 0)
+		return 0;
+
+	if (stb.st_dev != pstb.st_dev
+	    || stb.st_ino == pstb.st_ino)
+		return 1;
+	return 0;
+}
diff --git a/support/nfs/exports.c b/support/nfs/exports.c
index dfb241e..4d8665c 100644
--- a/support/nfs/exports.c
+++ b/support/nfs/exports.c
@@ -91,6 +91,7 @@ getexportent(int fromkernel, int fromexports)
 	ee.e_anongid = -2;
 	ee.e_squids = NULL;
 	ee.e_sqgids = NULL;
+	ee.e_mountpoint = NULL;
 	ee.e_nsquids = 0;
 	ee.e_nsqgids = 0;
 
@@ -187,6 +188,10 @@ putexportent(struct exportent *ep)
 	if (ep->e_flags & NFSEXP_FSID) {
 		fprintf(fp, "fsid=%d,", ep->e_fsid);
 	}
+	if (ep->e_mountpoint)
+		fprintf(fp, "mountpoint%s%s,",
+			ep->e_mountpoint[0]?"=":"", ep->e_mountpoint);
+
 	fprintf(fp, "mapping=");
 	switch (ep->e_maptype) {
 	case CLE_MAP_IDENT:
@@ -247,6 +252,8 @@ dupexportent(struct exportent *dst, struct exportent *src)
 		dst->e_sqgids = (int *) xmalloc(n * sizeof(int));
 		memcpy(dst->e_sqgids, src->e_sqgids, n * sizeof(int));
 	}
+	if (src->e_mountpoint)
+		dst->e_mountpoint = strdup(src->e_mountpoint);
 }
 
 struct exportent *
@@ -260,6 +267,7 @@ mkexportent(char *hname, char *path, char *options)
 	ee.e_anongid = -2;
 	ee.e_squids = NULL;
 	ee.e_sqgids = NULL;
+	ee.e_mountpoint = NULL;
 	ee.e_nsquids = 0;
 	ee.e_nsqgids = 0;
 
@@ -408,6 +416,15 @@ bad_option:
 				goto bad_option;
 			}
 			ep->e_flags |= NFSEXP_FSID;
+		} else if (strcmp(opt, "mountpoint")==0 ||
+			   strcmp(opt, "mp") == 0 ||
+			   strncmp(opt, "mountpoint=", 11)==0 ||
+			   strncmp(opt, "mp=", 3) == 0) {
+			char * mp = strchr(opt, '=');
+			if (mp)
+				ep->e_mountpoint = strdup(mp+1);
+			else
+				ep->e_mountpoint = strdup("");
 		} else {
 			xlog(L_ERROR, "%s:%d: unknown keyword \"%s\"\n",
 					flname, flline, opt);