text-based mount.nfs: Add functions to handle background mounting

[nfs-utils.git] / utils / mount / stropts.c

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index 13523f8814bd00aa6319435fa374a9e0e92de293..2d717fb296cde6ed9d9426339c6628e350b2c1ab 100644 (file)
--- 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
@@ -503,6 +524,146 @@ 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;
+}
+
+/*
+ * Handle "background" NFS mount [first try]
+ *
+ * Returns a valid mount command exit code.
+ *
+ * EX_BG should cause the caller to fork and invoke nfsmount_child.
+ */
+static int nfsmount_parent(const char *spec, const char *node,
+                          const char *type, char *hostname, int flags,
+                          struct mount_options *options,
+                          int fake, char **extra_opts)
+{
+       if (try_mount(spec, node, type, flags, options,
+                                       fake, extra_opts))
+               return EX_SUCCESS;
+
+       if (is_permanent_error(errno)) {
+               mount_error(spec, node, errno);
+               return EX_FAIL;
+       }
+
+       sys_mount_errors(hostname, errno, 1, 1);
+       return EX_BG;
+}
+
+/*
+ * Handle "background" NFS mount [retry daemon]
+ *
+ * Returns a valid mount command exit code: EX_SUCCESS if successful,
+ * EX_FAIL if a failure occurred.  There's nothing to catch the
+ * error return, though, so we use sys_mount_errors to log the
+ * failure.
+ */
+static int nfsmount_child(const char *spec, const char *node,
+                         const char *type, char *hostname, int flags,
+                         struct mount_options *options,
+                         int fake, char **extra_opts)
+{
+       unsigned int secs = 1;
+       time_t timeout = time(NULL);
+       char *retry;
+
+       timeout += 60 * 10000;          /* default: 10,000 minutes */
+       retry = po_get(options, "retry");
+       if (retry)
+               timeout += 60 * atoi(retry);
+
+       for (;;) {
+               if (sleep(secs))
+                       break;
+               secs <<= 1;
+               if (secs > 120)
+                       secs = 120;
+
+               if (try_mount(spec, node, type, flags, options,
+                                                       fake, extra_opts))
+                       return EX_SUCCESS;
+
+               if (is_permanent_error(errno))
+                       break;
+
+               if (time(NULL) > timeout)
+                       break;
+
+               sys_mount_errors(hostname, errno, 1, 1);
+       };
+
+       sys_mount_errors(hostname, errno, 1, 0);
+       return EX_FAIL;
+}
+
+/*
+ * Handle "background" NFS mount
+ *
+ * Returns a valid mount command exit code.
+ */
+static int nfsmount_bg(const char *spec, const char *node,
+                         const char *type, char *hostname, int flags,
+                         struct mount_options *options,
+                         int fake, int child, char **extra_opts)
+{
+       if (!child)
+               return nfsmount_parent(spec, node, type, hostname, flags,
+                                       options, fake, extra_opts);
+       else
+               return nfsmount_child(spec, node, type, hostname, flags,
+                                       options, fake, extra_opts);
+}
+
 /**
  * nfsmount_string - Mount an NFS file system using C string options
  * @spec: C string specifying remote share to mount ("hostname:path")