X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=blobdiff_plain;f=utils%2Fmount%2Fstropts.c;h=72480b7e0d279429b870d5b0a3db2107b95081cf;hp=fcc5b98ef5ec769585e4eb32c0eff61453020e31;hb=8c562efffb0e4e4e084f9605d0b9e1468b642eb4;hpb=5258d6c1aa4fd319976d1b13e27493adb57a4120

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index fcc5b98..72480b7 100644
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -237,6 +237,27 @@ static int set_mandatory_options(const char *type,
 	return 1;
 }
 
+/*
+ * Distinguish between permanent and temporary errors.
+ *
+ * Returns 0 if the passed-in error is temporary, thus the
+ * mount system call should be retried; returns one if the
+ * passed-in error is permanent, thus the mount system call
+ * should not be retried.
+ */
+static int is_permanent_error(int error)
+{
+	switch (error) {
+	case EACCES:
+	case ESTALE:
+	case ETIMEDOUT:
+	case ECONNREFUSED:
+		return 0;	/* temporary */
+	default:
+		return 1;	/* permanent */
+	}
+}
+
 /*
  * Reconstruct the mount option string based on a portmapper probe
  * of the server.  Returns one if the server's portmapper returned
@@ -368,10 +389,64 @@ err:
 }
 
 /*
- * Attempt an NFSv2/3 mount via a mount(2) system call.
+ * Retry an NFS mount that failed because the requested service isn't
+ * available on the server.
  *
  * Returns 1 if successful.  Otherwise, returns zero.
  * "errno" is set to reflect the individual error.
+ *
+ * Side effect: If the retry is successful, both 'options' and
+ * 'extra_opts' are updated to reflect the mount options that worked.
+ * If the retry fails, 'options' and 'extra_opts' are left unchanged.
+ */
+static int retry_nfsmount(const char *spec, const char *node,
+			int flags, struct mount_options *options,
+			int fake, char **extra_opts)
+{
+	struct mount_options *retry_options;
+	char *retry_str = NULL;
+
+	retry_options = rewrite_mount_options(*extra_opts);
+	if (!retry_options) {
+		errno = EIO;
+		return 0;
+	}
+
+	if (po_join(retry_options, &retry_str) == PO_FAILED) {
+		po_destroy(retry_options);
+		errno = EIO;
+		return 0;
+	}
+
+	if (verbose)
+		printf(_("%s: text-based options (retry): '%s'\n"),
+			progname, retry_str);
+
+	if (!mount(spec, node, "nfs",
+				flags & ~(MS_USER|MS_USERS), retry_str)) {
+		free(*extra_opts);
+		*extra_opts = retry_str;
+		po_replace(options, retry_options);
+		return 1;
+	}
+
+	po_destroy(retry_options);
+	free(retry_str);
+	return 0;
+}
+
+/*
+ * Attempt an NFSv2/3 mount via a mount(2) system call.  If the kernel
+ * claims the requested service isn't supported on the server, probe
+ * the server to see what's supported, rewrite the mount options,
+ * and retry the request.
+ *
+ * Returns 1 if successful.  Otherwise, returns zero.
+ * "errno" is set to reflect the individual error.
+ *
+ * Side effect: If the retry is successful, both 'options' and
+ * 'extra_opts' are updated to reflect the mount options that worked.
+ * If the retry fails, 'options' and 'extra_opts' are left unchanged.
  */
 static int try_nfs23mount(const char *spec, const char *node,
 			  int flags, struct mount_options *options,
@@ -392,7 +467,15 @@ static int try_nfs23mount(const char *spec, const char *node,
 	if (!mount(spec, node, "nfs",
 				flags & ~(MS_USER|MS_USERS), *extra_opts))
 		return 1;
-	return 0;
+
+	/*
+	 * The kernel returns EOPNOTSUPP if the RPC bind failed,
+	 * and EPROTONOSUPPORT if the version isn't supported.
+	 */
+	if (errno != EOPNOTSUPP && errno != EPROTONOSUPPORT)
+		return 0;
+
+	return retry_nfsmount(spec, node, flags, options, fake, extra_opts);
 }
 
 /*
@@ -441,6 +524,57 @@ static int try_mount(const char *spec, const char *node, const char *type,
 					options, fake, extra_opts);
 }
 
+/*
+ * Handle "foreground" NFS mounts.
+ *
+ * Retry the mount request for as long as the 'retry=' option says.
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfsmount_fg(const char *spec, const char *node,
+		       const char *type, int flags,
+		       struct mount_options *options, int fake,
+		       char **extra_opts)
+{
+	unsigned int secs = 1;
+	time_t timeout = time(NULL);
+	char *retry;
+
+	timeout += 60 * 2;		/* default: 2 minutes */
+	retry = po_get(options, "retry");
+	if (retry)
+		timeout += 60 * atoi(retry);
+
+	if (verbose)
+		printf(_("%s: timeout set for %s"),
+			progname, ctime(&timeout));
+
+	for (;;) {
+		if (try_mount(spec, node, type, flags,
+					options, fake, extra_opts))
+			return EX_SUCCESS;
+
+		if (is_permanent_error(errno))
+			break;
+
+		if (time(NULL) > timeout) {
+			errno = ETIMEDOUT;
+			break;
+		}
+
+		if (errno != ETIMEDOUT) {
+			if (sleep(secs))
+				break;
+			secs <<= 1;
+			if (secs > 10)
+				secs = 10;
+		}
+	};
+
+	mount_error(spec, node, errno);
+	return EX_FAIL;
+}
+
 /**
  * nfsmount_string - Mount an NFS file system using C string options
  * @spec: C string specifying remote share to mount ("hostname:path")
@@ -476,23 +610,11 @@ int nfsmount_string(const char *spec, const char *node, const char *type,
 	if (!set_mandatory_options(type, &saddr, options))
 		goto out;
 
-	if (po_join(options, extra_opts) == PO_FAILED) {
-		nfs_error(_("%s: internal option parsing error"), progname);
+	if (try_mount(spec, node, type, flags, options, fake, extra_opts)) {
+		mount_error(spec, node, errno);
 		goto out;
 	}
 
-	if (verbose)
-		printf(_("%s: text-based options: '%s'\n"),
-			progname, *extra_opts);
-
-	if (!fake) {
-		if (mount(spec, node, type,
-				flags & ~(MS_USER|MS_USERS), *extra_opts)) {
-			mount_error(spec, node, errno);
-			goto out;
-		}
-	}
-
 	retval = EX_SUCCESS;
 
 out: