text-based mount command: add function to parse numeric mount options

Introduce a function that is especially for parsing keyword mount options
that take a numeric value.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/utils/mount/parse_opt.c b/utils/mount/parse_opt.c
index cb398bd2d4d714fd5aa1ab798f3763ed0e9a80f4..f61d0dd6470da10448d7cc3d9df3f0762667c405 100644 (file)
--- a/utils/mount/parse_opt.c
+++ b/utils/mount/parse_opt.c
@@ -36,6 +36,10 @@
  */
 
 
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
 #include <ctype.h>
 #include <unistd.h>
 #include <stdio.h>
@@ -365,6 +369,57 @@ char *po_get(struct mount_options *options, char *keyword)
        return NULL;
 }
 
+/**
+ * po_get_numeric - return numeric value of rightmost instance of keyword option
+ * @options: pointer to mount options
+ * @keyword: pointer to a C string containing option keyword for which to search
+ * @value: OUT: set to the value of the keyword
+ *
+ * This is specifically for parsing keyword options that take only a numeric
+ * value.  If multiple instances of the same option are present in a mount
+ * option list, the rightmost instance is always the effective one.
+ *
+ * Returns:
+ *     * PO_FOUND if the keyword was found and the value is numeric; @value is
+ *       set to the keyword's value
+ *     * PO_NOT_FOUND if the keyword was not found
+ *     * PO_BAD_VALUE if the keyword was found, but the value is not numeric
+ *
+ * These last two are separate in case the caller wants to warn about bad mount
+ * options instead of silently using a default.
+ */
+#ifdef HAVE_STRTOL
+po_found_t po_get_numeric(struct mount_options *options, char *keyword, long *value)
+{
+       char *option, *endptr;
+       long tmp;
+
+       option = po_get(options, keyword);
+       if (option == NULL)
+               return PO_NOT_FOUND;
+
+       errno = 0;
+       tmp = strtol(option, &endptr, 10);
+       if (errno == 0 && endptr != option) {
+               *value = tmp;
+               return PO_FOUND;
+       }
+       return PO_BAD_VALUE;
+}
+#else  /* HAVE_STRTOL */
+po_found_t po_get_numeric(struct mount_options *options, char *keyword, long *value)
+{
+       char *option;
+
+       option = po_get(options, keyword);
+       if (option == NULL)
+               return PO_NOT_FOUND;
+
+       *value = atoi(option);
+       return PO_FOUND;
+}
+#endif /* HAVE_STRTOL */
+
 /**
  * po_rightmost - determine the relative position of two options
  * @options: pointer to mount options

diff --git a/utils/mount/parse_opt.h b/utils/mount/parse_opt.h
index fb003c3030a8839200bb03e0b1e808b8b03a55a0..199630f85625b69d8d5074e95450e4ac5cd15a67 100644 (file)
--- a/utils/mount/parse_opt.h
+++ b/utils/mount/parse_opt.h
@@ -32,6 +32,7 @@ typedef enum {
 typedef enum {
        PO_NOT_FOUND = 0,
        PO_FOUND = 1,
+       PO_BAD_VALUE = 2,
 } po_found_t;
 
 typedef enum {
@@ -50,6 +51,8 @@ po_return_t           po_join(struct mount_options *, char **);
 po_return_t            po_append(struct mount_options *, char *);
 po_found_t             po_contains(struct mount_options *, char *);
 char *                 po_get(struct mount_options *, char *);
+po_found_t             po_get_numeric(struct mount_options *,
+                                       char *, long *);
 po_rightmost_t         po_rightmost(struct mount_options *, char *, char *);
 po_found_t             po_remove_all(struct mount_options *, char *);
 void                   po_destroy(struct mount_options *);