From: Neil Brown <neilb@suse.de>
Date: Mon, 19 Mar 2007 00:41:21 +0000 (+1100)
Subject: Allow exporting of a subfilesystem when 'crossmnt' is set.
X-Git-Tag: nfs-utils-1-1-0-rc1~46
X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=commitdiff_plain;h=323d1c4d69b65ab36d951aca8473ceb02171ab08

Allow exporting of a subfilesystem when 'crossmnt' is set.

If we are asked to export a filesystem which is not explicitly
exported, but an ancestor is exported as 'crossmnt', export the
filesystems with the same options as the ancestor.

This is the first step to making 'crossmnt' effectively export
a tree of filesystems.
---

diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 5612a9e..734ddd8 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -52,7 +52,7 @@ enum nfsd_fsid {
  * Record is terminated with newline.
  *
  */
-int cache_export_ent(char *domain, struct exportent *exp);
+int cache_export_ent(char *domain, struct exportent *exp, char *p);
 
 
 char *lbuf  = NULL;
@@ -408,7 +408,7 @@ void nfsd_fh(FILE *f)
 	}
 
 	if (found)
-		cache_export_ent(dom, found);
+		cache_export_ent(dom, found, found->e_path);
 
 	qword_print(f, dom);
 	qword_printint(f, fsidtype);
@@ -466,7 +466,7 @@ static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *ex
 		write_fsloc(f, exp, path);
  		if (exp->e_uuid == NULL) {
  			char u[16];
- 			if (get_uuid(exp->e_path, NULL, 16, u)) {
+ 			if (get_uuid(path, NULL, 16, u)) {
  				qword_print(f, "uuid");
  				qword_printhex(f, u, 16);
  			}
@@ -598,7 +598,7 @@ int cache_process_req(fd_set *readfds)
  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
  */
 
-int cache_export_ent(char *domain, struct exportent *exp)
+int cache_export_ent(char *domain, struct exportent *exp, char *path)
 {
 	int err;
 	FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
@@ -606,12 +606,52 @@ int cache_export_ent(char *domain, struct exportent *exp)
 		return -1;
 
 	err = dump_to_cache(f, domain, exp->e_path, exp);
-	fclose(f);
 	mountlist_add(domain, exp->e_path);
+
+	while ((exp->e_flags & NFSEXP_CROSSMOUNT) && path) {
+		/* really an 'if', but we can break out of
+		 * a 'while' more easily */
+		/* Look along 'path' for other filesystems
+		 * and export them with the same options
+		 */
+		struct stat stb;
+		int l = strlen(exp->e_path);
+		int dev;
+
+		if (strlen(path) <= l || path[l] != '/' ||
+		    strncmp(exp->e_path, path, l) != 0)
+			break;
+		if (stat(exp->e_path, &stb) != 0)
+			break;
+		dev = stb.st_dev;
+		while(path[l] == '/') {
+			char c;
+			int err;
+
+			l++;
+			while (path[l] != '/' && path[l])
+				l++;
+			c = path[l];
+			path[l] = 0;
+			err = lstat(path, &stb);
+			path[l] = c;
+			if (err < 0)
+				break;
+			if (stb.st_dev == dev)
+				continue;
+			dev = stb.st_dev;
+			path[l] = 0;
+			dump_to_cache(f, domain, path, exp);
+			path[l] = c;
+		}
+		break;
+	}
+
+	fclose(f);
 	return err;
 }
 
-int cache_export(nfs_export *exp)
+int cache_export(nfs_export *exp, char *path)
 {
 	int err;
 	FILE *f;
@@ -628,7 +668,7 @@ int cache_export(nfs_export *exp)
 	
 	fclose(f);
 
-	err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export)
+	err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export, path)
 		|| err;
 	return err;
 }
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index fc9a73c..04141d1 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -29,7 +29,7 @@
 
 extern void	cache_open(void);
 extern struct nfs_fh_len *cache_get_filehandle(nfs_export *exp, int len, char *p);
-extern int cache_export(nfs_export *exp);
+extern int cache_export(nfs_export *exp, char *path);
 
 extern void my_svc_run(void);
 
@@ -399,7 +399,7 @@ get_rootfh(struct svc_req *rqstp, dirpath *path, mountstat3 *error, int v3)
 		     p, strerror(errno));
 		*error = NFSERR_NOENT;
 	} else if (estb.st_dev != stb.st_dev
-		   /* && (!new_cache || !(exp->m_export.e_flags & NFSEXP_CROSSMOUNT)) */
+		   && (!new_cache || !(exp->m_export.e_flags & NFSEXP_CROSSMOUNT))
 		) {
 		xlog(L_WARNING, "request to export directory %s below nearest filesystem %s",
 		     p, exp->m_export.e_path);
@@ -418,7 +418,7 @@ get_rootfh(struct svc_req *rqstp, dirpath *path, mountstat3 *error, int v3)
 		 */
 		struct nfs_fh_len  *fh;
 
-		if (cache_export(exp)) {
+		if (cache_export(exp, p)) {
 			*error = NFSERR_ACCES;
 			return NULL;
 		}